WO2022213183A1 - Procédés et systèmes de communication à bande ultralarge (uwb) - Google Patents

Procédés et systèmes de communication à bande ultralarge (uwb) Download PDF

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Publication number
WO2022213183A1
WO2022213183A1 PCT/CA2022/050510 CA2022050510W WO2022213183A1 WO 2022213183 A1 WO2022213183 A1 WO 2022213183A1 CA 2022050510 W CA2022050510 W CA 2022050510W WO 2022213183 A1 WO2022213183 A1 WO 2022213183A1
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WIPO (PCT)
Prior art keywords
uwb
transceiver
audio
data
frame
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PCT/CA2022/050510
Other languages
English (en)
Inventor
Frederik NABKI
Dominic DESLANDES
Michiel SOER
Gabriel MORIN-LAPORTE
Mohammad TAHERZADEH-SANI
Raphael GUIMOND
Mohammad Rahman
Original Assignee
Nabki Frederik
Deslandes Dominic
Soer Michiel
Morin Laporte Gabriel
Taherzadeh Sani Mohammad
Guimond Raphael
Mohammad Rahman
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
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Publication date
Application filed by Nabki Frederik, Deslandes Dominic, Soer Michiel, Morin Laporte Gabriel, Taherzadeh Sani Mohammad, Guimond Raphael, Mohammad Rahman filed Critical Nabki Frederik
Priority to CN202280040395.0A priority Critical patent/CN117480734A/zh
Priority to EP22783719.2A priority patent/EP4320730A1/fr
Publication of WO2022213183A1 publication Critical patent/WO2022213183A1/fr

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Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
    • H04B1/38—Transceivers, i.e. devices in which transmitter and receiver form a structural unit and in which at least one part is used for functions of transmitting and receiving
    • H04B1/40—Circuits
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
    • G01D21/00—Measuring or testing not otherwise provided for

Definitions

  • This invention relates to ultra-wideband wireless communication systems and more particularly to configuring ultra-wideband transmitters and receivers for enhanced ultra- wideband wireless link performance for said communication systems.
  • Ultra-Wideband (UWB) technology is a wireless technology for the transmission of large amounts of digital data as modulated coded impulses over a very wide frequency spectrum with very low power over a short distance.
  • Such pulse based transmission being an alternative to transmitting using a sinusoidal wave which is then turned on or off, to represent the digital states, as employed within today’s wireless communication standards and systems such as IEEE 802.11 (Wi-Fi), IEEE 802.15 wireless personal area networks (PANs), IEEE 802.16 (WiMAX), Universal Mobile Telecommunications System (UMTS), Global System for Mobile Communications (GSM), General Packet Radio Service (GPRS), and those accessing the Industrial, Scientific and Medical (ISM) bands, and International Mobile Telecommunications-2000 (IMT -2000) .
  • Wi-Fi Wi-Fi
  • PANs wireless personal area networks
  • WiMAX wireless personal area networks
  • UMTS Universal Mobile Telecommunications System
  • GSM Global System for Mobile Communications
  • GPRS General Packet Radio Service
  • ISM International Mobile T
  • UWB systems are well-suited to short-distance applications in a variety of environments, such as depicted in Figure 1 including peripheral and device interconnections, as exemplified by first residential environment 110, sensor networks, as exemplified by second residential environment 120, control and communications, as exemplified by industrial environment 130, medical systems, as exemplified by medical imaging 150, and personal area networks (PAN), as exemplified by PAN 140.
  • PAN personal area networks Due to low emission levels permitted by regulatory agencies such UWB systems tend to be short-range indoor applications but it would be evident that a variety of other applications may be considered where such regulatory restrictions are relaxed and / or not present addressing military and civilian requirements for communications between individuals, electronic devices, control centers, and electronic systems for example.
  • UWB transmitters, UWB receivers and UWB transceivers it would be beneficial for UWB transmitters, UWB receivers and UWB transceivers to provide flexible configuration and management by the electronic devices, such as portable electronic devices, fixed electronic devices, and sensors for example, to enable their deployment. It would be further beneficial for such UWB transmitters, UWB receivers and UWB transceivers to support a software development kit and/or hardware development kits enabling enterprises etc. to embed the UWB transmitters, UWB receivers and UWB transceivers into their devices with ease.
  • a method comprising: providing an ultra-wideband (UWB) transceiver; and automatically configuring a gain of the UWB transceiver for a frame in dependence upon a determination with respect to a preceding frame; wherein the configuration proceeds via a first process if the frame has been rejected; the configuration proceeds via a second process if the frame has been lost; the configuration proceeds via a third process if the frame has been received; and the third process employs a current index of the gain, a signal strength of the receive frame in ADC steps and a gain settings table.
  • UWB ultra-wideband
  • a method comprising: providing an ultra-wideband (UWB) transceiver; and providing a bridge to couple the UWB transceiver to at least one of an external data source and an external data sink.
  • UWB ultra-wideband
  • a method of establishing a wireless link comprising: providing an ultra-wideband (UWB) transceiver; wherein the UWB transceiver executes a process relating to an aspect of a wireless link established or being established between the UWB transceiver and another transceiver.
  • a method comprising: providing an ultra-wideband (UWB) transceiver; and providing a software development kit to execute a process; wherein the process relates to at least one of: an aspect of a wireless link established or being established between the UWB transceiver and another transceiver; and an aspect of the UWB transceiver.
  • UWB ultra-wideband
  • a device comprising: an ultra-wideband (UWB) transceiver; and at least one of: a hardware development kit; and an evaluation development kit; wherein control of the device is provided via a software development kit which executes a process; wherein the process relates to at least one of: an aspect of a wireless link established or being established between the UWB transceiver and another transceiver; an aspect of the UWB transceiver; and an aspect of at least one of the HDK and EDK.
  • UWB ultra-wideband
  • a device comprising: an ultra-wideband (UWB) transceiver; a solar harvester; a sensor; and an electrical storage coupled to the solar harvester to receive electrical charge to be stored and to the UWB transceiver to power the UWB transceiver; wherein the device transmits readings acquired by the sensor via the UWB transceiver; and the device automatically configures itself in dependence upon the available power within the electrical storage.
  • UWB ultra-wideband
  • a method comprising: providing an ultra-wideband (UWB) transceiver; and automatically configuring a beacon frame to be transmitted within a sequence of frames comprising data being transmitted by the UWB transceiver.
  • UWB ultra-wideband
  • a method comprising: providing a sensor module comprising at least a sensor, a photovoltaic cell and an ultra- wideband (UWB) transceiver; acquiring sensor data with the sensor; and transmitting the sensor data with the UWB transceiver; wherein the sensor module is installed within an indoor environment; and the sensor module is powered solely via the photovoltaic cell converting light from lighting within the indoor environment.
  • UWB ultra- wideband
  • Figure 1 depicts applications of UWB transmitters, receivers, and systems according to embodiments of the invention
  • Figure 2 depicts a block diagram of a UWB transmitter according to an embodiment of the invention
  • Figure 3A depicts a block diagram of a UWB transmitter according to an embodiment of the invention supporting biphasic phase scrambling
  • Figure 3B depicts a block diagram of a UWB transmitter according to an embodiment of the invention employing dynamically configurable and programmable pulse sequences;
  • Figure 3C depicts schematically a multi -pulse symbol UWB protocol according to an embodiment of the invention;
  • Figure 3D depicts pulses from a UWB transmitter according to an embodiment of the invention at three different frequencies;
  • Figure 3E depicts a pulse sequence for a bit transmitted by a UWB transmitter according to an embodiment of the invention together with its emitted power spectrum
  • Figure 3F depicts a pulse sequence for a bit transmitted by a UWB transmitter according to an embodiment of the invention together with its emitted power spectrum with and without biphasic phase scrambling;
  • Figure 4 depicts a block diagram of a UWB receiver according to an embodiment of the invention.
  • Figure 5 depicts a receiver circuit schematic for a UWB receiver / transceiver according to an embodiment of the invention
  • Figure 6 depicts a circuit schematic for a UWB transceiver according to an embodiment of the invention.
  • Figure 7 depicts a frequency hopping configuration for UWB devices according to an embodiment of the invention.
  • Figure 8 depicts a frequency hopping configuration for UWB devices according to an embodiment of the invention.
  • FIG. 9 depicts a UWB transceiver according to an embodiment of the invention supporting multiple antennas supporting dual standards for its physical layer (PHY);
  • PHY physical layer
  • Figure 10A depicts an optical micrograph of an application specific integrated circuit (ASIC) embodiment of a UWB transceiver according to an embodiment of the invention as depicted in Figure 7;
  • ASIC application specific integrated circuit
  • FIG. 10B depicts an exemplary top level schematic of a hardware development kit (HDK) according to an embodiment of the invention supporting UWB devices and software development kit (SDK) according to embodiments of the invention with radio modules employing UWB transceiver;
  • HDK hardware development kit
  • SDK software development kit
  • Figure 11 depicts an exemplary configuration for a self-contained UWB node according to an embodiment of the invention exploiting UWB devices according to embodiments of the invention with solar harvesting for power generation;
  • Figure 12 depicts an exemplary link layer overview for a UWB system according to an embodiment of the invention exploiting UWB devices, HDKs and SDKs according to embodiments of the invention;
  • Figure 13 depicts an exemplary flow chart for a lower link layer process exploited by UWB devices according to an embodiment of the invention
  • Figure 14 depicts an exemplary lower link layer use process exploited UWB devices according to embodiments of the invention
  • Figure 15 depicts an exemplary lower link layer state machine for a UWB device according to an embodiment of the invention.
  • Figure 16 depicts an exemplary clear channel assessment sequence diagram for a UWB device according to an embodiment of the invention.
  • Figures 17 and 18 depict Tx and Rx lower link layer sequence diagrams for a UWB device according to an embodiment of the invention
  • Figure 19 depicts a higher link layer process for a UWB device according to an embodiment of the invention.
  • Figure 20 depicts higher link layer state machines for master and slave UWB devices according to an embodiment of the invention
  • Figure 21 depicts timing synchronization between UWB devices according to an embodiment of the invention.
  • Figure 22 depicts enqueue and dequeue exampled for random access memory (RAM) allocation within UWB devices according to an embodiment of the invention
  • Figure 23 depicts a UWB transceiver module according to an embodiment of the invention in conjunction with a carrier board with and without a protective case;
  • Figure 24 depicts UWB transceivers with dipole antennae according to embodiments of the invention together with their resulting gain radiation patterns
  • Figure 25 depicts UWB transceivers with monopole antennae according to embodiments of the invention together with their resulting gain radiation patterns
  • Figure 26 depicts a graphical user interface (GUI) for a home window of a software application controlling and/or configuring a UWB device according to an embodiment of the invention
  • Figure 27 depicts audio mode GUIs for transmitter and receiver configuration for a software application controlling and/or configuring UWB devices according to an embodiment of the invention
  • Figure 28 depicts statistics mode GUIs for transmitter and receiver configuration for a software application controlling and/or configuring a UWB device according to an embodiment of the invention
  • Figure 29 depicts an advanced mode GUI for a software application controlling and/or configuring a UWB device according to an embodiment of the invention
  • Figure 30 depicts ranging mode GUIs for transmitter and receiver configuration for a software application controlling and/or configuring a UWB device according to an embodiment of the invention
  • Figure 31 depicts a plotter mode GUI and zoomed time domain GUI for a software application controlling and/or configuring a UWB device according to an embodiment of the invention
  • Figure 32A depicts exemplary master-slave interactions according to an embodiment of the invention between a master UWB device and multiple slave devices;
  • Figure 32B depicts exemplary timing implementations according to embodiments of the invention for a SPI Protocol Core of a UWB Transceiver such as depicted in Figure 9;
  • Figure 33 depicts a process flow for an audio stream according to an embodiment of the invention;
  • Figure 34 depicts process flows for pair of electronic devices with UWB transceivers supporting an audio stream according to an embodiment of the invention
  • Figure 35 depicts a process flow for loopback within electronic devices with UWB transceivers supporting an audio stream according to an embodiment of the invention
  • Figure 36 depicts a process flow for multicasting with electronic devices with UWB transceivers supporting an audio stream according to an embodiment of the invention
  • Figure 37 depicts system block diagrams of an electronic device with UWB transceiver supporting applications including audio streaming according to an embodiment of the invention
  • Figure 38 depicts an exemplary flow diagram for an audio application interfaced to UWB transceivers within electronic devices according to an embodiment of the invention
  • Figure 39 depicts an exemplary process flow for an audio stream with 3 processing stages according to an embodiment of the invention
  • Figure 40 depicts audio latency measurements established with electronic devices employing UWB transceivers according to embodiments of the invention
  • Figure 41 depicts an exemplary configuration for a wireless interface between electronic devices employing UWB wireless transceivers host interfaces via a serial peripheral interface (SPI) pipe;
  • SPI serial peripheral interface
  • Figure 42 depicts exemplary timing information for the UWB interface employed within the system of Figure 41;
  • Figure 43 depicts an exemplary data structure for the UWB transmission within the system of Figure 41 ;
  • Figure 44 depicts a timing diagram for a SPI pipe according to an embodiment of the invention showing half-duplex transfer, pausing and full duplex transfer;
  • Figure 45 depicts a timing diagram for the SPI pipe to allow an SPI master device to write continuously without stopping any transaction
  • Figure 46 depicts a timing diagram for the SPI pipe where an SPI master device is reading slave device configuration parameters
  • Figure 47 depicts a timing diagram for the SPI pipe where an SPI master device is writing slave device configuration parameters
  • Figure 48 depicts measured values for a UWB link employing UWB transceivers according to an embodiment of the invention extracted via the SPI pipe;
  • Figure 49 depicts measured results upon a logic analyzer for an SPI to SPI interface with UWB transceivers according to an embodiment of the invention
  • Figure 50 depicts the emitted power spectrum of the UWB transceiver providing a 3Mbps unidirectional link
  • Figure 51 depicts an exemplary configuration of a head mounted device (HMD) interfaced to a pair of controllers via UWB transceivers according to an embodiment of the invention
  • Figure 52 depicts an exemplary structure of a superframe for UWB transmissions between UWB transceivers according to an embodiment of the invention
  • Figure 53 depicts exemplary structures for data frames, acknowledgement, beacon and controller data frames within the superframe for UWB transmissions between UWB transceivers according to an embodiment of the invention
  • Figures 54 to 56 depict power error rates for an HMD and associated dual controller as measured employing UWB transceivers according to an embodiment of the invention
  • Figure 57 depicts the average power of the HMD and controller UWB transceivers within the configuration depicted in Figure 51;
  • Figure 58 depicts the peak power of the HMD and controller UWB transceivers within the configuration depicted in Figure 51;
  • Figures 59 depicts latency measurements obtained when a latency mode of the UWB transceivers within the configuration depicted in Figure 51 is deactivated and activated respectively;
  • Figure 60 depicts an exemplary synchronization measurement between UWB transceivers within the configuration depicted in Figure 51;
  • Figure 61 depicts an exemplary gain loop employed within UWB transceivers according to an embodiment of the invention
  • Figure 62 depicts time slot and scheduler structures according to an embodiment of the invention together with associated API commands and usage;
  • Figure 63 depicts a beacon scheme according to an embodiment of the invention.
  • Figure 64 depicts a time slot incrementing structure according to an embodiment of the invention.
  • Figure 65 depicts the frequency versus time performance of prior art audio transmission protocols relative to an embodiment of the invention relative to an original compact disc (CD) quality source providing a discrete 10kHz tone
  • Figure 66 depicts the frequency versus time performance of prior art audio transmission protocols relative to an embodiment of the invention relative to an original CD quality source providing periodic audio impulses.
  • the present invention is directed to ultra-wideband wireless communication systems and more particularly to configuring ultra-wideband transmitters and receivers for enhanced ultra-wideband wireless link performance for said communication systems.
  • references to terms “including,” “comprising,” “consisting” and grammatical variants thereof do not preclude the addition of one or more components, features, steps, integers, or groups thereof and that the terms are not to be construed as specifying components, features, steps or integers.
  • the phrase “consisting essentially of,” and grammatical variants thereof, when used herein is not to be construed as excluding additional components, steps, features integers or groups thereof but rather that the additional features, integers, steps, components or groups thereof do not materially alter the basic and novel characteristics of the claimed composition, device or method. If the specification or claims refer to “an additional” element, that does not preclude there being more than one of the additional element.
  • a “portable electronic device” may refer to, but is not limited to, a wireless device used for communications and other applications that requires a battery or other independent form of energy for power. This includes devices, but is not limited to, such as a cellular telephone, smartphone, personal digital assistant (PDA), portable computer, pager, portable multimedia player, portable gaming console, laptop computer, tablet computer, a wearable device, fitness tracker, head mounted display (HMD), an electronic reader or a peripheral device.
  • PDA personal digital assistant
  • portable computer pager
  • portable multimedia player portable gaming console
  • laptop computer laptop computer
  • tablet computer tablet computer
  • HMD head mounted display
  • an electronic reader or a peripheral device such as a cellular telephone, smartphone, personal digital assistant (PDA), portable computer, pager, portable multimedia player, portable gaming console, laptop computer, tablet computer, a wearable device, fitness tracker, head mounted display (HMD), an electronic reader or a peripheral device.
  • HMD head mounted display
  • a “fixed electronic device” may refer to, but is not limited to, a wireless and /or wired device used for communications and other applications that requires connection to a fixed interface to obtain power. This includes, but is not limited to, a laptop computer, a personal computer, a computer server, a kiosk, a gaming console, a digital set-top box, an analog set-top box, an Internet enabled appliance, an Internet enabled television, a multimedia player, or a peripheral device.
  • a “peripheral device” as used herein may refer to, but is not limited to, a wireless device used for providing input to a PED and/or FED and/or generating output from a PED and/or FED.
  • a peripheral device or peripheral accordingly, is used to put information into and/or get information out of the computer and refers to hardware components that are wirelessly connected to a PED, FED or wearable device.
  • a peripheral device may provide electronic content, receive electronic content, or convert electronic content.
  • a peripheral device may include, but not be limited to, a mouse, a keyboard, a stylus, a display, a solid state memory device, a hard disk drive, a wireless router, a wireless repeater, a network adapter, an interface supporting devices with a standard connection to interface then to the PED, FED, or wearable device (such interfaces being for example USB or LightningTM), microphone, loudspeakers, headphones, head mounted display (HMD), headset, a printer, a scanner, multi-function printer, a motion tracker, a sensor, an alarm, image scanner, barcode scanner, game controller, webcam, camera, and a haptic interface.
  • a peripheral device may itself be a PED, FED or wearable device.
  • Electronic content (also referred to as “content” or “digital content”) as used herein may refer to, but is not limited to, any type of content that exists in the form of digital data as stored, transmitted, received and / or converted wherein one or more of these steps may be analog although generally these steps will be digital.
  • Digital content include, but are not limited to, information that is digitally broadcast, streamed, or contained in discrete files.
  • types of digital content include popular media types such as MP3, JPG, AVI, TIFF, AAC, TXT, RTF, HTML, XHTML, PDF, XLS, SVG, WMA, MP4, FLV, and PPT, for example, as well as others, see for example http://en.wikipedia.org/wiki/List_of_file_formats.
  • digital content may include any type of digital information, e.g. digitally updated weather forecast, a GPS map, an eBook, a photograph, a video, a VineTM, a blog posting, a FacebookTM posting, a TwitterTM tweet, online TV, etc.
  • the digital content may be any digital data that is at least one of generated, selected, created, modified, and transmitted in response to a user request, said request may be a query, a search, a trigger, an alarm, and a message for example.
  • a “software application” (commonly referred to as an “application” or “app”) as used herein may refer to, but is not limited to, a “software application,” an element of a “software suite,” a computer program designed to allow an individual to perform an activity, a computer program designed to allow an electronic device to perform an activity, and a computer program designed to communicate with local and / or remote electronic devices.
  • An application thus differs from an operating system (which runs a computer), a utility (which performs maintenance or general-purpose chores), and a programming tools (with which computer programs are created).
  • an application is generally presented in respect of software permanently and / or temporarily installed upon a PED, FED, and/or wearable device.
  • GUI graphical user interface
  • PED personal electronic device
  • FED field-effect transistor
  • Wearable Device software application or operating system which allows a user to interact through graphical icons with or without an audio indicator for the selection of features, actions, etc. rather than a text-based user interface, a typed command label or text navigation.
  • a “profile” as used herein may refer to, but is not limited to, a computer and/or microprocessor readable data file comprising data relating to settings and/or limits of an adult device.
  • Such profiles may be established by a manufacturer / supplier / provider of a device, service, etc. or they may be established by a user through a user interface for a device, a service or a PED/FED in communication with a device, another device, a server or a service provider etc.
  • a “computer file” (commonly known as a file) as used herein may refer to, but is not limited to, a computer resource for recording data discretely in a computer storage device, this data being electronic content.
  • a file may be defined by one of different types of computer files, designed for different purposes.
  • a file can be opened, read, modified, copied, and closed with one or more software applications an arbitrary number of times.
  • files are organized in a file system which can be used on numerous different types of storage device exploiting different kinds of media which keeps track of where the files are located on the storage device(s) and enables user access.
  • the format of a file is typically defined by its content since a file is solely a container for data, although, on some platforms the format is usually indicated by its filename extension, specifying the rules for how the bytes must be organized and interpreted meaningfully.
  • a “wireless interface” as used herein may refer to, but is not limited to, an interface for a PED, FED, or Wearable Device which exploits electromagnetic signals transmitted through the air. Typically, these electromagnetic signals are microwave signals and/or RF signals.
  • a “wired interface” as used herein may refer to, but is not limited to, an interface for a PED, FED, or Wearable Device which exploits electrical signals transmitted through an electrical cable or cables.
  • a wired interface involves a plug or socket on the electronic device which interfaces to a matching socket or plug on the electrical cable(s).
  • An electrical cable may include, but not be limited, coaxial cable, an electrical mains cable, an electrical cable for serial communications, an electrical cable for parallel communications comprising multiple signal lines, etc.
  • a “software development kit” as used herein may refer to, but is not limited to, a collection of software development tools provided as an installable package.
  • the SDK facilitates the creation of applications by having a compiler, debugger and perhaps a software framework.
  • An SDK may be specific to a hardware platform and operating system combination.
  • An SDK may take the form of an application programming interface (API) or APIs in the form of on-device libraries of reusable functions used to interface to a particular programming language, or it may be as complex as hardware-specific tools that can communicate with a particular embedded system.
  • API application programming interface
  • Common tools within an SDK include debugging facilities and other utilities, often presented in an integrated development environment (IDE).
  • UWB offers many potential advantages such as high datarate, low-cost implementation, and low transmit power, ranging, multipath immunity, and low interference.
  • the Federal Communications Commission (FCC) regulations for UWB reserved the unlicensed frequency band between 3.1GHz and 10.6GHz for indoor UWB wireless communication system wherein the low regulated transmitted power allows such UWB systems to coexist with other licensed and unlicensed narrowband systems. Therefore, the limited resources of spectrum can be used more efficiently.
  • FCC Federal Communications Commission
  • an UWB system has a capacity much higher than the current narrowband systems for short range applications.
  • Two possible techniques for implementing UWB communications are Impulse Radio (IR) UWB and multi -carrier or multi -band (MB) UWB.
  • IR Impulse Radio
  • MB multi -band
  • IR-UWB exploits the transmission of ultra-short (of the order of nanosecond) pulses, although in some instances in order to increase the processing gain more than one pulse represents a symbol.
  • MB -UWB systems use orthogonal frequency division multiplexing (OFDM) techniques to transmit the information on each of the sub-bands. Whilst OFDM has several good properties, including high spectral efficiency, robustness to RF and multi-path interferences. However, it has several drawbacks such as up and down conversion, requiring mixers and their associated high power consumption, and is very sensitive to inaccuracies in frequency, clock, and phase. Similarly, nonlinear amplification destroys the orthogonality of OFDM.
  • MB-UWB is not suitable for low-power and low cost applications.
  • IR-UWB offers several advantages, including unlicensed usage of several gigahertz of spectrum, offers great flexibility of spectrum usage, and adaptive transceiver designs can be used for optimizing system performance as a function of the datarate, operation range, available power, demanded quality of service, and user preference.
  • multi-Gb/s data-rate transmission over very short range is possible and due to the ultra-short pulses within IR-UWB it is very robust against multipath interference, and more multipath components can be resolved at the receiver in some implementations, resulting in higher performance.
  • ultra-short pulses support sub-centimeter ranging whilst the lack of up and down conversion allows for reduced implementation costs and lower power transceiver implementations.
  • ultra-short pulses and low power transmissions make IR-UWB communications hard to eavesdrop upon.
  • both the pulse generator and the on-demand oscillator are digitally tunable in order to provide control over the pulse bandwidth and center frequency.
  • the IR-UWB transmitter is designed to allow very quick frequency adjustments on the order of the pulse repetition rate (PRR).
  • PRR pulse repetition rate
  • this technique provides the same advantages as MB-OFDM in respect of spectrum configurability, achieved by sequentially changing the transmitted spectrum using a frequency hopping scheme, whilst maintaining the benefits of IR-UWB. Further, by providing advanced duty cycling with fast power up time combined with On-Off Shift Keying (OOK) modulation the IR-UWB according to embodiments of the invention allows significant reductions in power consumption by exploiting the low duty cycle of a UWB symbol and the fact that only half the symbols require sending energy.
  • OOK On-Off Shift Keying
  • PSD power spectral density
  • Equation (1) Equation (1) between E p , the transmitted energy per pulse, the maximum spectral power S , the bandwidth B , the bit rate R b and the number of pulses per bits N ppb
  • PHY Physical layer
  • PLM pulse-position-modulation
  • BPSK bi-phasic shift keying
  • UWB transmitters and energy based UWB receivers which are capable of generating and adapting to a variety of IR-UWB pulses and bit encoding schemes thereby supporting communications from both IR-UWB transmitters compliant to IEEE standards as well as those that are non-standard.
  • FIG. 2 there is depicted schematically an exemplary architecture for an IR-UWB transmitter 200 according to embodiments of the invention which is composed of five main blocks plus the antenna.
  • a programmable impulse is produced by a pulse generator 230 at clocked intervals when the data signal from AND gate 210 is high based upon control signals presented to the AND gate 210.
  • the pulses from the pulse generator 230 are then up-converted with a programmable multi -loop digitally controlled ring oscillator (DCRO) 240.
  • the output from the DCRO 240 is then coupled to a variable gain amplifier (VGA) 250 in order to compensate for any frequency dependency of the pulse amplitude.
  • VGA variable gain amplifier
  • a driver 260 feeds the antenna 270, overcoming typical package parasitics, such as arising from packaging the transceiver within a quad-flat no-leads (QFN) package.
  • a power cycling controller 220 dynamically switches on or off these functional blocks when the data signal is low.
  • FIG. 3 A there is depicted schematically a block diagram 300 of an exemplary IR-UWB transmitter according to embodiments of the invention supporting biphasic phase scrambling.
  • the Biphasic Phase Shifting IR- UWB (BPS-IR-UWB) transmitter comprises 6 main blocks.
  • First a programmable impulse is produced by a pulse generator 330 at clocked intervals when the data signal from AND gate 310 is high based upon control signals presented to the AND gate 310.
  • the pulses from the pulse generator 330 are then up-converted with a programmable multi-loop digitally controlled ring oscillator (DCRO) 340.
  • the output from the DCRO 340 is then coupled to a dual-output amplifier (VGA) 350 both in order to compensate for any frequency dependency of the pulse amplitude but also to generate dual phase shifted output signals that are coupled to a switch 360 which selects one of the two signals to couple to the output power amplifier (driver) 380 under the action of the switch control signal “S” applied to the switch 360.
  • VGA dual-output amplifier
  • the output power amplifier 380 feeds the antenna 370, overcoming typical package parasitics, such as arising from packaging the transceiver within a quad-flat no-leads (QFN) package.
  • a power cycling controller 320 dynamically switches on or off these functional blocks when the data signal “PC” is low.
  • a BPS-IR-UWB transmitter transmits pulses with or without phase shift based upon the control signal “S” applied to switch 360. If this control signal is now fed from a random data generator or a pseudo random data generator then the resulting pulses coupled to the antenna of the BPS-IR-UWB transmitter will be pseudo-randomly or randomly phase shifted.
  • FIG. 3B there is depicted schematically a block diagram 3000 of an exemplary IR-UWB transmitter according to embodiments of the invention.
  • a Pulse Pattern block 3010 holds a configuration for the pulses used to represent the current symbol.
  • DLL Delay Locked Loop
  • the rising edge of each clock phase represents the start of one pulse in the symbol pulse bundle.
  • a multiplexer 3020 is triggered by the edges of the clock phases and selects the configuration of the current pulse out of the Pulse Pattern block 3010.
  • a pulse generator (Pulser) 3050 generates pulses with a pulse width set by the multiplexer 3020 and enables the Digitally Controlled Oscillator (DCO) 3040 and Power Amplifier (PA) 3060.
  • the DCO 3040 When enabled, the DCO 3040 generates a Gaussian shaped pulse with frequency set by the multiplexer 3020, which is then amplified by the PA 3060 and radiated by the antenna 3070.
  • the Pulse Pattern block 3010 establishes the pulses for a symbol or sequence of symbols.
  • updating the Pulse Pattern block 3010 adjusts the pulse sequence employed for each symbol and accordingly the Pulse Pattern block 3010 may be dynamically updated based upon one or more factors including, but not limited to, network environment data, predetermined sequence, date, time, geographic location, signal-to-noise ratio (SNR) of received signals, and regulatory mask.
  • SNR signal-to-noise ratio
  • FIG. 3C there is depicted schematically a multi-pulse symbol UWB protocol according to an embodiment of the invention.
  • first image 3100A there is depicted a bit 3160 comprising a series of sub-pulses 3160 A to 3160C which are each at frequencies j ⁇ f 2 .L .
  • the multi -pulse spectrum 3180 of a symbol is depicted in second image 3100B as obtained conceptually (phase scrambling is omitted for clarity) by summing the individual pulse spectra of the sub-pulses 3160A to 3160C, which increases the bandwidth whilst increasing the total symbol duration, in contrast with single pulse prior art methods, whilst maintaining the maximum power below the UWB mask 3120.
  • This allows the symbol energy to be maximized while relaxing the timing requirements and level of synchronization required at the receiver.
  • An arbitrary number of pulses with different sets of parameters may be included within a bundle to tailor the pulse spectrum to a given requirement.
  • FIG. 3D there are depicted the measured pulse shapes for three different frequency setting of a UWB transmitter according to an embodiment of the invention such as described and depicted in Figure 2 or Figure 3A without biphasic phase scrambling according to WO/2015/103,692.
  • first trace 3300A a pulse bundle representing a bit being transmitted such as described within WO/2015/103,692 is depicted whilst second trace 3300B depicts the resulting power spectrum density (PSD). It is evident that this allows for managing the PSD of the final signal through the parameters for each pulse within the frequency hopping sequence.
  • the pulse sequence depicted comprising 4 pulses at 2.4GHz, 2 pulses at 3.5GHz, and 3 pulses at 4.0GHz.
  • the resulting PSD fills the spectrum at around -58dBm over the entire band.
  • FIG. 3F there are depicted the power spectrum and pulse train for a pulse bundle according to WO 2016/191,851 and as depicted in Figure 3 A supporting operating over a frequency range from approximately 3 GHz to approximately 7GHz.
  • First and second images 3400A and 3400B respectively representing the power spectrum and pulse sequence wherein there is no random frequency or phase scrambling during the generation and transmission.
  • Third and fourth images 3400C and 3400D depict the results for random frequency and random phase scrambling of the pulses wherein phase is set per pulse through data established by a pseudo-random data generator. Accordingly, it would be evident that when comparing first and third images 3400A and 3400C that the introduction of random frequency and random phase shifting reduces the spectral lines significantly within the emitted spectrum of a UWB transmitter according to embodiments of the invention.
  • FIG. 4 there is depicted schematically the architecture of an IR-UWB receiver 400 according to embodiments of the invention.
  • the signal from an IR- UWB transmitter is received via an antenna 410 and coupled to a low noise amplifier (UNA) 420 followed by first amplifier 430 wherein the resulting signal is squared by squaring circuit 440 in order to evaluate the amount of energy in the signal.
  • the output of the squaring circuit 440 is then amplified with second amplifier 450, integrated with integration circuit 460 and evaluated by a flash ADC 470 to generate the output signals.
  • Power Cycling Controller 480 which, in a similar manner to the power cycling controller 220 of IR-UWB transmitter 200 in Figure 2, dynamically powers up and down the UNA 420, first and second amplifiers 430 and 450 respectively, squaring circuit 440, and flash ADC 470 to further reduce power consumption in dependence of the circuit’s requirements.
  • FIG. 5 there is depicted a schematic of a receiver 500 according to an embodiment of the invention.
  • the RF signal from the antenna 510 is initially amplified by a Uow Noise Amplifier (UNA) 520 before being passed to a two stage RF amplifier (AMP1) 530.
  • a first squaring mixer (MIX1) 540 multiplies the signal with itself to convert to the Intermediate Frequency (IF).
  • a three-stage Variable Gain Amplifier (VGA) 550 amplifies the signal further and implements a bandpass filter function.
  • the VGA 550 output is then coupled to a second squaring mixer (MIX2) 560 which down-converts the signal to the baseband frequency.
  • a parallel integrator (INTI and INT2) sums the signal energy, which is digitized by the Analog-to-Digital Converters (ADC1 and ADC2) and sent to a digital processor (not depicted for clarity).
  • a battery f 3.00 ⁇ v BATT ⁇ 3.6 V powers a low-frequency crystal oscillator 615, sleep counter 620 and bandgap reference 610, all of which are typically always operational although the bandgap reference 610 could be duty cycled within other embodiments of the invention without altering the scope of the claimed invention).
  • Their power consumption limits the minimum power consumption of the system to sub-microwatt level.
  • An integrated buck DC-DC converter 605 is powered by the battery when the system is not in sleep mode, and this provides the supply voltage to the rest of the system with high conversion efficiency.
  • the startup time of the DC-DC converter 605 is on the order of several symbol periods in order to minimize wasted energy.
  • the PLL 655 is active to provide the base clock for the system.
  • the receiver 625 and DLL 660 have dedicated power down controls and are only activated during frame transmission / reception. Further, the transmitter is also power cycled through its all-digital architecture which is not depicted as having a separate control.
  • the power consumption of the digital synthesized blocks is low due to the low base clock (e.g. 20 MHz).
  • a power-cycled transceiver achieves linear scaling of power consumption with datarate, thus achieving constant energy efficiency.
  • multiple data rates are obtained by adjusting the length of the sleep period, with the maximum attainable datarate determined by the symbol rate in the frame itself.
  • the power consumption during sleep must be lower than the average power consumption.
  • powering down the PLL is not required when its consumption does not significantly degrade the overall efficiency.
  • the whole system except the bandgap reference, crystal oscillator, and sleep counter can be shut down during sleep mode. In this case, the millisecond range startup time of the PLL can be insignificant compared to the sleep period, and overall efficiency is also not significantly degraded.
  • the UWB transceiver 600 also comprises a receive / transmit switch 690 coupled to the antenna to selectively couple the transmitter 6000 or receiver 625 to the antenna during transmission and reception respectively.
  • the UWB transceiver 600 also comprises a spectrum configuration circuit 665 (equivalent to Pulse Pattern 3010 in transmitter 3000 in Figure 3B), PHY Processing circuit 650, Link Controller 645, Buffer and Interface circuit 640, and PHY Formatting circuit 635.
  • the UWB transceiver 600 communicates via Link Controller 645 to the Client 605.
  • Link Controller 645 may communicate using a wired protocol (e.g., serial peripheral interface (SPI)) to Client 605, for example.
  • SPI serial peripheral interface
  • UWB transmitters UWB receivers, and UWB transceivers.
  • the inventors have described such devices within WO/2020/186,332 “Methods and Systems for Ultra- wideband Receivers”; WO/2020/186,334 “Ultra-wideband Link Configuration Methods and Systems”; WO/2020/186,333 “Ultra-wideband Transmitter and Receiver Circuits”; US 17/201,475 “Energy Efficient Ultra-Wideband Impulse Radio Systems and Methods”; US 16/261,860 “Systems and Methods for Spectrally Efficient and Energy Efficient Ultra- Wideband Impulse Radios with Scalable Datarates”; and US 16/938,208 “Methods and Systems Relating to Ultra-wideband Broadcasting”, the entire content of which are incorporated herein by reference.
  • UWB Devices which may refer to a transmitter and transceiver or receiver and transceiver as would be evident to one of skill in the art by the function being described with respect to them
  • each UWB Device has its own hopping sequence.
  • this hopping sequence for each UWB Device increments by 1 at each transmission. Accordingly, for a UWB Device to listen to another UWB Device it must know the hopping sequence of the transmitting UWB device.
  • An advantage of this approach is that it is easy to configure devices and for such configured devices to be certified.
  • each device has a channel hopping object defining its channel hoping sequence.
  • Figure 7 depicts a frequency hopping configuration for UWB devices according to this embodiment of the invention where the index of the channel hopping sequence is incremented for each transmission by a UWB Device. Accordingly, Figure 7 depicts 3 Device 1 710, Device 720 and Device 730 together with their channel array sequences. Table 740 denotes a series of time slots together with a channel associated with that time slot together with which device can transmit and which can receive in that particular timeslot.
  • a UWB Device may be communicating 12 other UWB Devices then it will require 12 arrays to be updated when there is a change, i.e. when each UWB Device transmits. Maintaining these arrays is difficult and particularly so when these have to updated in real time during runtime of each UWB Device. Accordingly, there is no global view of the RF channels on the network comprising these devices. If a UWB Devices timeslot is changed then it will be necessary to change its channel hopping array to keep the desired sequence over the air.
  • the inventors propose that alternatively the channel hopping sequence is known by every device in the network. Every UWB Device frequency index hops according to the same array. The index hop is determined by the timeslot number of the device. For example, if Device 1 710 is done listening on timeslot #3, sleeps on timeslot #4 and then listens again on timeslot#5, then it will increment the hop index by 2.
  • FIG. 8 there is depicted a frequency hopping configuration for UWB devices according to an embodiment of the invention wherein Device 1 810, Device 2 820, Device 3 830 are depicted together with their channel arrays, which are identical, namely first to third channel arrays 840 to 860 respectively.
  • Table 870 depicts the same time slot and channel sequence together with the identity of which device is transmitting and which is receiving. Accordingly, the arrows depicted around each of the channel arrays show the resulting migration of an index pointer within each of the channel arrays as the time slots advance. As noted above through factors such as sleep, not receiving, not transmitting etc. the hop sequence is different for each device.
  • Device 1 810 transmits on the first timeslot, fourth to six timeslots and ninth and tenth timeslots and receives on the second, third, seventh and eighth timeslots.
  • Device 1 810 transmits on the first timeslot, fourth to six timeslots and ninth and tenth timeslots and receives on the second, third, seventh and eighth timeslots.
  • 2 820 transmits on the second and seventh timeslots whilst receiving on the first, fifth, sixth and tenth timeslots.
  • Device 3 830 transmits on the third and eighth timeslots and received on the fourth and ninth timeslots. Accordingly, the resulting frequency sequence for Device 2820, which operates on 6 timeslots, becomes channels 5, 2, 1,2, 3, 2 and for Device 3 which operates on 4 timeslots, becomes channels 3, 4, 4, 5.
  • a beacon transmission from a master UWB Device may distribute the channel hopping sequence via broadcast (or other mechanism) to allow dynamic network updates. This allows also for the channel hopping sequence to less hard coded than dynamically coded. As such a UWB Device may initially listen, obtain the beacon signal with the channel plan, update its array and beginning transmitting / receiving within the network.
  • UWB Devices may be employed in conjunction with a Software Development Kit (SDK).
  • SDK Software Development Kit
  • Embodiments of the invention may employ or provide an SDK comprising, typically as a minimum:
  • WPS wireless protocol stack
  • the SDK may also comprise one or more of:
  • Hardware support e.g. a board support package (BSP) containing hardware-specific drivers and other routines to allow an operating system to function with a particular hardware environment).
  • BSP board support package
  • the wireless protocol stack may support synchronized UWB transmission links (synchronized links) with variable datarate, variable RF settings, a “Stop-and-Wait Automatic Repeat Request” (ARQ), channel hopping, frame statistics and a public API.
  • WPS wireless protocol stack
  • the audio framework of the SDK may enable a range of audio applications based upon allowing configuration for unidirectional operation, bidirectional operation, configurable stream quality (e.g. using sampling rate conversion), controllable volume amplitude, and clock tracking and correction.
  • SDKs may support a WPS Concurrency Mechanism as well as WPS Multiple Radio Support. These SDKs according to embodiments of the invention may enable the UWB Device with an EVK hardware to provide an RF module which receives data from / provides data to an external electronic device, e.g. PED, FED, Wearable Device, Sensor, etc. through a standard interface such as Serial Peripheral Interface (SPI), universal asynchronous receiver-transmitter (UART), etc.
  • SPI Serial Peripheral Interface
  • UART universal asynchronous receiver-transmitter
  • Time division multiple access where radio transfers occur in time at a similar rate and of an identical duration in each network (typically capacity limits provide for 15-25 % of the time slots to be left empty for retransmission purposes;
  • FDMA Frequency division multiple access
  • CCA Clear channel assessment
  • Syncword filtering where networks operate on different syncwords to ensure the rejection of a frame from another network (the syncword being used to synchronize a data transmission, for example by indicating the end of header information and the start of data).
  • the received signal strength indicator (RSSI) of each radio UWB Device
  • RSSI received signal strength indicator
  • the inventors have established WPS ranging demonstrations, WPS audio demonstrations and concurrency with WPS audio demonstrations.
  • the inventors have also established graphical user interface (GUI) link configuration tools for user to employ providing extended advanced modes of operation, RF parameters control, schedule control, network control.
  • GUI graphical user interface
  • the inventors have established a Wireless Sensor Node (WSK) such as described below in respect of Figure 11 providing demonstration of compatibility with Intemet-of-Things (IoT) concepts as well as providing support for spatial awareness (e.g., within application such as drones etc.) and star network topologies. Further the SDK provides support for audio broadcasting and audio multicasting.
  • WSK Wireless Sensor Node
  • Embodiments of the invention at the UWB Device, SDK, and Hardware Development Kit (HDK), with respect to audio, have the functionality to provide:
  • I2S Inter-IC Sound
  • Audio mixing wherein a receiver mixes multiple incoming independent streams of data
  • Embodiments of the invention at the UWB Device and WPS have the functionality to provide:
  • FIG. 10A depicts an optical micrograph of an application specific integrated circuit (ASIC) embodiment of a UWB transceiver according to an embodiment of the invention as depicted in Figure 7.
  • Embodiments of this circuit with a second generation iteration of the underlying design have yielded ⁇ 4-5dB receiver sensitivity improvement (-80 dBm), 4-5dB increase in transmitter maximum output power, operational support for 1.2V I/O, datarates to 40.96Mb/s, improved modulation for ISI and time domain efficiency as well as supporting antenna diversity.
  • a typical implementation of the UB transceiver of Figure 7 as depicted in Figure 10A operates over 6.1 GHz - 9.3 GHz with ⁇ 10dB bandwidth.
  • FIG. 9 there is depicted a third generation UWB Transceiver 900 according to an embodiment of the invention supporting multiple antennas and dual standards for its physical layer (PHY). Accordingly, as depicted the UWB Transceiver 900 comprises:
  • Spark Backend 935 providing a PHY established by Spark Microsystems Inc. as implemented in their SRI 120 ASIC;
  • ASIC Hardware Bus (AHB) 940 interconnecting the IEEE Backend 930 and Spark Backend 935 to a Bridge 965, Application Core 945, Stack Core 950, RAM 955 and DMA 960.
  • Application Core 945 comprising a microcontroller unit (MCU) for processing application related data and applications;
  • MCU microcontroller unit
  • Stack Core 950 comprising a second MCU processing the wireless protocol stack and wireless protocol related applications
  • RAM Random Access Memory
  • DMA Direct Memory Access
  • Bridge 965 for bridging communications from the AHB and an ASIC Protocol Bus (APB) 970;
  • APB 970 which handles communications between the Bridge 965, Power Management 975, Clock Management 980 and first to fourth I/O 990 A to 990D respectively; • Power Management 975 which provides control of the sequenced power up / power down / sleep of the Transceiver Front End 920 and first to N Tx/Rx Blocks 9000(1) to 9000(N) as well as other elements of the UWB Transceiver 900;
  • Clock Management 980 which receives the base clock and generates the multiple clocks required by the different functional blocks of the UWB Transceiver 900;
  • First to fourth I/O 990A to 990D depicted as providing quad serial peripheral interface (QSPI), Inter-IC Sound (I2S), Inter-Integrated Circuit (I2C) and universal asynchronous receiver-transmitter (UART) interfaces to the UWB Transceiver 900 for data I/O and control I/O.
  • QSPI quad serial peripheral interface
  • I2S Inter-IC Sound
  • I2C Inter-Integrated Circuit
  • UART universal asynchronous receiver-transmitter
  • UWB Transceiver 900 therefore provides support for both a proprietary PHY (Spark Microsystems Inc.) and IEEE UWB PHY. IEEE 802.15.4z providing data rates up to 31.2Mb/s (versus upon to 40.96Mb/s on the proprietary PHY) on channels 5-12 (6.1 - 9.0 GHz).
  • the Multiple transmit / receive blocks, depicted as first to N Tx/Rx Blocks 9000(1) to 9000(N), with parallel RF chains provide for support of angle of arrival (AoA) estimation where N>2.
  • FIG. 10B depicts an exemplary top level schematic of a hardware development kit (HDK) 1000 according to an embodiment of the invention supporting UWB devices and software development kit (SDK) according to embodiments of the invention with first and second Radio Modules 1010 and 1020, each employing a UWB Transceiver according to an embodiment of the invention.
  • the HDK 1000 also comprising an MCU 1030 as well UART, I2C, I2S, and serial peripheral interface (SPI) connectors for I/O, analog-to-digital converters (ADCs), as well as SPI connections between the first and second Radio Modules 1010 and 1020 and MCU 1030 etc.
  • the HDK 1000 providing, conjunction, with the SDK the flexibility for peripherals via UART, SPI, I2C, I2S as well as applications with ultra-low power, high datarate, low latency, ranging and support for complex networks.
  • FIG 11 depicts an exemplary configuration for a self-contained UWB node or Wireless Sensor Kit (WSK) 1100 according to an embodiment of the invention exploiting UWB devices according to embodiments of the invention with solar harvesting for power generation.
  • the WSK 1100 providing a compact platform for low power sensor applications exploiting UWB Devices according to embodiments of the invention.
  • the Sensors 1120 may be motion (movement), light and weather.
  • other sensors may be employed including, but not limited to, environmental sensors, medical sensors, biological sensors, physiological sensors, chemical sensors, ambient environment sensors, position sensors, acceleration sensors, orientation sensors, and neurological sensors.
  • the WSK 1100 further comprises a USB Interface 1130 (for programming, firmware updates etc.), a Daughter Board 1140 supporting a battery or solar harvester, MCU 1150, UWB Transceiver 1120 (Spark Radio Module), Current Measurement Interface 1170 and Debug Interface 1180.
  • the WSK or other embodiments of the invention may support photovoltaic cells for power generation. These photovoltaic cells may convert exterior ambient light, interior ambient light or light from lighting within an indoor environment.
  • FIG. 12 depicts an exemplary Link Layer 1200 overview for a Stack employable with UWB systems according to an embodiment of the invention exploiting UWB devices, HDKs and SDKs according to embodiments of the invention.
  • the Stack implements the necessary protocols in order to create an RF link between UWB transceivers. Multiple modes of operation can be selected depending on the application and the required performances where the profile selection can yield different trade-offs in terms of range, power consumption, latency and datarate.
  • the Link Layer 1200 comprises:
  • NVM Non-Volatile Memory
  • Link High 1220, Link Low 1240, MCU Peripheral Abstraction Layer 1295A, and Cross-Layer Queue 1295B being accessible through an API.
  • MCU Peripheral Abstraction Layer 1295 A provides the Stack with a consistent interface between the application code and system hardware, regardless of the hardware platform. It provides an interface for the radio interface (e.g. SPI, general purpose IO (GPIO), and interrupt request (IRQ)), software interrupt (SWI), time delay and “critical section.”
  • the radio interface provides an interface for multiple, e.g. 2 UWB Devices (commonly referred to as radios), depending on the platform allowing Radio Selection to set the current radio for all subsequent function calls.
  • SPI functions are used to send and receive data to the radios for this there are two basic groups of functions. The first group uses the SPI peripheral directly and are blocking, waiting for the transfer to complete. The second group uses DMA and are non- blocking.
  • the GPIO provides a functions interface to the various GPIOs, such as debug enable, radio reset and shutdown.
  • the IRQ functions provide for enabling or disabling the radio IRQs.
  • the SWI is used by the Cross-Layer Queue 1295B as part of its dequeue/enqueue trigger mechanism. With the time delay this function implements a blocking time delay with a lmS resolution whilst the Critical Section enter and exit functions are used to bracket code that must not be interrupted.
  • Lower Link Layer The Lower Link Layer (Link Low 1240) is designed to abstract all register accesses to the radio its user to perform the following tasks using simple human readable configuration structures:
  • FIG. 13 depicts an exemplary flow chart for a lower link layer process exploited by UWB devices according to an embodiment of the invention when the user sends a command.
  • the user is operating in a completely synchronous manner with the lower link layer. Data transfers and radio configurations should be exchanged at a precise time. Asynchronous data transfer is possible using the following general concept: the presence or absence of user data to be sent during each user callback event modulates the link throughput. As long as the average SRI 0X0 duty cycling scheduled by the user is greater than the application’s frame generation rate, no information should be lost. The mechanism used to achieve this will be explained below.
  • the internal SRI 0X0 timer has the granularity of the SRI 0X0 PLL clock which is 1/20A8MHZ ⁇ 50ns.
  • the timer value is set to 0 every time the radio wakes up.
  • the user passes the timer compare value as a parameter. In this manner, the user can request that a frame to be transmitted or received at precisely the desired amount of PPL clock cycles after the last time the SRI 0X0 woke up.
  • Figure 13 a sequence diagram for a general use case is depicted in Figure 14.
  • SR10X0 IRQs are used to determine the outcome of user commands and react accordingly.
  • the main IRQ events used are shown on Table 1 below.
  • the ”SIG RX” output signal will come with a frame containing user data and information about the frame, like LQI and others.
  • ”SIG RX FAIL” or ”SIG RX TIMEOUT” indicate that the frame was lost.
  • CCA Clear Channel Assessment
  • the SR 10X0 will do a CCA check before transmissions.
  • the ’’IRQ CCA FAIL” interrupt will be generated by the SRI 0X0 and counted by the lower link layer state machine.
  • Another transmission attempt will be executed automatically after a configured delay “a.” This process will repeat itself for a number of times “n” set by the user at initialization. If a CCA check succeeds or the maximum number of failures is reached, the frame will be transmitted.
  • the sequence of events just described can be added to the diagram shown in Figure 14 resulting in Figure 16.
  • Transmitting a long frame is done by sending the first part on the frame to the TX FIFO before a transmission occurs (i.e. during the ’entry/’ phase of the lower link layer state machine). See Figure 2. The 3 remaining parts will be sent during the SR10X0 transmission. Every time the TX FIFO load is lowered bellow a threshold by the SR10X0 transmitting data, the ’’IRQ BUFLOAD” will trigger and the lower link layer state machine will send another part of the frame to the TX FIFO.
  • the desired band number must not be higher than the number of bands configured at initialization.
  • the SR10X0 RX timeout value is only used for RX commands.
  • SPI Transfers Different SPI transfers occur within the lower link layer state machine during user command execution. Those transfers can use DMA and as such will minimize frame to frame overhead.
  • a “Status Read Transfer” is a simple read access of the two SR10X0 status registers are done every time an IRQ is triggered. The source of the IRQ will be used to determine the actions to take during the processing of a state. This transfer occurs during the ’do/’ phase of the lower link layer state machine, see Figure 13.
  • An “Information Read Transfer” is a blocking DMA SPI transfer happens at every reception of a frame in order to extract the following information from the radio:
  • a “RX FIFO Read Transfer” is a non-blocking DMA SPI transfer is used to read user data and the link header from the SR10X0 RX FIFO. This transfer occurs during the ’do/’ phase of the lower link layer state machine, see Figure 13.
  • a “Frame Configuration Write Transfer” is a non-blocking DMA SPI transfer is used to configure a series of SRI 0X0 registers according to frame parameters and the specific state. This includes:
  • Spectral Module This module contains everything needed for optimal RF transfer. It is used by the lower link layer state machine to configure the SR 10X0 RF block. This module executes the following tasks and sub-tasks:
  • TX pulse pattern and RX Filters Configuration Based on the user configuration sent at initialization, data structures compatible with the SR 10X0 registers will be created in order to configure the radio RF block for optimal transfer on each band. These structures will be used by the lower link state machine during the frame configuration write transfer.
  • User parameters include the following:
  • Dynamic RX gain selection is used to select proper RX gain to optimize RF transfers and avoid saturation in the receiver. This is done by monitoring the SR10X0 signal RSSI every time a frame is received and adjusting the gain. The adjusted gain value will be in effect at the next reception attempt. The RSSI is obtained from the lower link layer state machine during the information read transfer. The resulting gain value is used during the next frame configuration write transfer of any RX command. This process is done independently for every band.
  • Clear Channel Assessment threshold is calculated based on the average noise floor. This is done by monitoring the SRI 0X0 signal RNSI every time a frame is received and computing a running average. The RNSI is obtained from the lower link layer state machine during the information read transfer. An offset provided by the user at initialization is then added to the average and the SR 10X0 is configured with the resulting value at every TX frame configuration write transfer. The maximum sample size used to calculate the running average, for example this may be 10. This process is done independently for every band. A filter is also available to remove sudden peaks in RNSI value and can be configured by the user. [00205] Statistics Module
  • a statistics module is available for the user to monitor link quality.
  • the statistics available independently for each band are the following.
  • All LQI information is collected during the information read transfer of any received frame.
  • the Higher Link Layer (Link High 1220 in Figure 12) is a module which allows it’s user to perform the following tasks using simple human readable configuration structures.
  • the higher link layer state machine main function is to send a periodic sequence of lower link layer transfer commands based on a schedule configured by the user. Depending on the state and the outcome of transfer commands, actions will be taken to ensure synchronization. Transferred frames will be dispatch to proper services based on their type allowing the link layer to exchange data internally in addition to user data. Built-in re transmissions and software filtering are available. The generic process used is shown on Figure 19.
  • ’’Syncing” State The master is following the user schedule and will enter the ’’synced” state when an auto reply frame is received. The slave is adding a time offset to the scheduled SRI 0X0 timer compare value and will enter the ’’synced” state when a frame is received. This way, the slave listening window will collide with the master transmission.
  • ’’Synced” State The master is following the user schedule and will enter the ’’syncing” state when a predefined number of consecutive auto reply frames were lost. The slave is following the user schedule, adding a synchronization time offset to the scheduled SR 10X0 timer compare value, see section below on synchronization. It will enter the ’’syncing” state when a predefined number of consecutive frames are lost.
  • Synchronization The accurate synchronization is achieved by keeping track of the waiting time t w between wake up and detection of the syncword for the slave in RX. When a frame is received, this value t w is returned by the lower link layer and compared with a target time t T . A time offset to is calculated and added to the next slot time t s to compensate for any drift.
  • An example of how the system reacts for the case of a slave waking up too late is depicted in Figure 21. In this manner a slave is re-synchronized to the master every time it receives with an accuracy of l/20A8MHz ⁇ 50ns.
  • the coarse duty cycling time t s is based on the time slots information provided by the scheduler module and configured by the application.
  • Scheduler Module The scheduler performs the following tasks.
  • Time Slot Configuration When configuring a time slot, the user should provide the following.
  • the ID of transmitting and receiving node refer to the unique device ID configured by the user at initialization.
  • the transmission cross layer queue is where the higher link layer state machine will look for data when transmitting on a user time slot.
  • the reception cross layer queue is where the higher link layer state machine will put data when receiving on a user time slot.
  • the cross layer queue is a message pool of fixed sized buffers allowing processes to efficiently transfer data. It features:
  • the queue is implemented as a singly linked list of elements called nodes. All the nodes are of a fixed size and they reside in a static location in RAM.
  • First Image 2200A in Figure 22 depicts the Queue 2210 within the context of an overall queue structure.
  • nodes are a basic element of the queue.
  • a node represents an area in the message pool of a fixed size.
  • the application layer must only use a User Data section.
  • a node format according to an embodiment of the invention comprises a top section reserved for link information, a section for a link header, the user data section, and a section for a next node.
  • the link header, user data and next node forming a radio packet.
  • the Next Node pointer is automatically populated whenever the node is enqueued.
  • the Reserved for Link and Link Header sections are for the exclusive use of the link layer.
  • a queue is a structure which contains the information presented in Table 2.
  • Free Queue During system initialization, the queue module will create the free queue. This is where all nodes are obtained (queue get free node) and where they must return when the nodes are no longer needed (queue free node). The free queue also acts as the root queue pointing to all subsequent queues created by system processes.
  • Interrupts The queues allow for a software interrupt (SWI) to be triggered when a dequeue and/or enqueue is performed.
  • SWI software interrupt
  • the interrupt priority for SWI is set to just below the audio and radio interrupts. For example the interrupt levels may be defined as outlined in Table 3 below.
  • an application In order to use the SWI an application must first register a callback function with the SWI handler.
  • UWB transceiver module according to an embodiment of the invention in conjunction with a carrier board without (first Image 2300A) and with (second Image 2300B) a protective case.
  • the UWB transceiver ASIC is packaged as UWB Transceiver 2310 in a 4 mm x 4 mm QFN package which is mounted to a daughter board that integrates an antenna where the daughter board is mounted to a mother board with MCU etc.
  • Configurations with dipole and monopole antennas may be implemented.
  • the dipole antenna provided on exemplary modules covers a frequency range going from approximately 3.3 to 5.7 GHz for one UWB Transceiver circuit (e.g.
  • the dipole exhibits a maximum gain of 4.8 dBi at 5 GHz for the SR1010 and of 4.7 dBi at 8.25 GHz for the SR1020.
  • First Image 2400 A in Figure 24 depicts the SE1010 UWB transceiver with dipole antenna according to embodiments of the invention together with its resulting gain radiation pattern in second Image 2400B in Figure 24.
  • Third image 2400C in Figure 24 depicts the SR1020 transceiver with dipole antenna whilst fourth Image 2400D depicts the resulting gain radiation pattern.
  • the monopole antenna is vertically polarized and provides an omni-directional radiation pattern with a maximum realized gain of 3.5 dBi at 5.5 GHz for the SR1010 and of 3 dBi at 7 GHz for the SR1020. Its -10 dB impedance bandwidth starts at 3.5 GHz and extends up to 6 GHz for the SR1010 and starts at 6.3 GHz and extends up to 9.35 GHz for the SR1020.
  • First Image 2500A in Figure 25 depicts the SE1010 UWB transceiver with monopole antenna according to embodiments of the invention together with its resulting gain radiation pattern in second Image 2500B in Figure 25.
  • Third image 2500C in Figure 25 depicts the SR1020 transceiver with monopole antenna whilst fourth Image 2500D depicts the resulting gain radiation pattern.
  • GUI graphical user interface
  • the “Display all USB devices” checkbox is used when the user’s computer does not automatically detect a connected device or devices.
  • the user can select different modes, audio, stats, advanced and ranging.
  • the GUI in conjunction with a HDK or WSK allows for evaluation of an audio streaming mode of the UWB transceivers which represents a real-time, high datarate application.
  • the audio signal or audio stream may not pre-processed or post-processed, nor the audio stream compressed.
  • the results indicated within Figures 27 to 31 were obtained under this scenario using an analog audio signal digitized with a standard commercial ADC of an audio codec, the MaximTM stereo codec MAX9809, streamed to the first UWB transceiver according to an embodiment of the invention, transmitted wirelessly, and then received on the other end by another UWB transceiver according to an embodiment of the invention.
  • the received audio being then streamed to another codec and converted to an analog signal by its DAC for playback.
  • FIG. 27 depicts first and second audio mode GUIs 2700 A and 2700B respectively for transmitter and receiver UWB transceivers respectively within a software application controlling and/or configuring UWB devices according to an embodiment of the invention.
  • the evaluation GUI provides 4 audio presets, these being:
  • Bandwidth 1.2 GHz (SR1010 only) or 1.6 GHz. This setting controls the bandwidth usage. The user may change this based on different environments, such as indoor/outdoor, open fields, or 5GHz Wi-Fi interference.
  • An exemplary configuration being to use the 1.2 GHz BW configuration in environments with strong 5 GHz Wi-Fi interference.
  • Other embodiments of the invention may provide for automatic detection of the 5 GHz Wi-Fi interference and enable the system to automatically compensate for different link conditions, as the UWB Transceivers according to embodiments of the invention are capable of modifying their spectrum usage in real-time over its operating band.
  • Some audio settings may be manually adjusted, such as:
  • Latency Three settings are available: 5 ms, 10 ms and 20 ms. The latency corresponds to the size of the audio buffers used by the system. More latency translates into a more resilient audio link.
  • the Mono mode has the advantage of allowing more retransmissions compared to the Stereo mode since it requires half the channel capacity, which translates into more range.
  • the audio transmitter will send only the left samples, and the receiver will use them to feed the left and right channel.
  • Link ID There may be multiple Link identities (Link IDs) to select from, for example 4, depending on the audio quality. In order for two units to communicate, they must share the same Link ID. Link IDs are useful when multiple concurrent audio links are running in the same vicinity. When running concurrent audio links, each different Link ID should be established for different pairs of UWB transceivers. For example, a first Link ID may be associated with UWB transceivers providing audio streaming to a pair of headphones from a smartphone whilst another Link ID is associated with another pair of UWB transceivers streaming the audio to a loudspeaker from a PC in the same room.
  • FIG. 28 depicts first and second statistics mode GUIs 2800A and 2800B for transmitter and receiver UWB transceivers respectively within a software application controlling and/or configuring a UWB device according to an embodiment of the invention.
  • Exemplary statistics options provided to the user within the GUI may include:
  • Sent & ACKed The number of unique audio packets transmitted.
  • Sent & Not ACKed The number of audio packets retransmitted due to not receiving an ACK.
  • Idle The number of retransmission opportunities that were not taken due to the link being healthy.
  • TX Audio Buffer The number of milliseconds of audio in the transmitter’s audio buffer. In a normal situation, this buffer is almost empty.
  • Link Utilization The proportion of time used for transmitting and retransmitting audio packets over the total link capacity. The formula is as follows:
  • RX Audio Buffer The number of milliseconds of audio in the receiver’s audio buffer. In a normal situation, this buffer is almost full.
  • Statistics Mode allows users to evaluate unidirectional randomized data transfers at different rates. A lower datarate preset will allow for a greater communication distance. For example, 8 statistics presets may be presented to the user:
  • Datarate This is the payload datarate (not the over-the-air datarate) which are:
  • Data Size This is the payload data size (not the over-the-air data size).
  • Sleep Level All presets use the Idle sleep level except the Very Low preset which uses the Deep Sleep level mode wherein the majority of the UWB Transceiver is powered down when not transmitting or receiving.
  • Bandwidth 1.2 GHz (SR1010 only) or 1.6 GHz. This setting controls the bandwidth usage. The user may change this based on different environments, such as indoor/outdoor, open fields, or 5GHz Wi-Fi interference although within other embodiments of the invention the UWB Transceiver may provide spectrum sensing and accordingly automatically compensate for different link conditions, as the UWB Transceivers according to embodiments of the invention are capable of modifying their spectrum usage in real-time over the operating band.
  • the GUI in Figure 29 establishes the link as unidirectional in this mode, the statistics are computed at the receiver. The statistics will only be displayed in the receiver window.
  • Advanced Mode This mode allows users to manually set various transceiver and link parameters and test with unidirectional transfers according to these applied settings. In this mode some combinations of settings might not result in a working link nor respect the emission limits of local standards for UWB transmissions.
  • GUI for a software application controlling and/or configuring a UWB device according to an embodiment of the invention. For example, within an advanced mode the user may be able to configure the following parameters with respect to the UWB Transceivers:
  • Sleep Level Determines the power consumption of the transceiver when asleep and plays on the maximum duty cycle achievable. This may for example be: o Idle: Light Sleep Level. Takes approximately 500 ns to get back to active state. Typical current consumption is 250 mA in this mode at 3.0 V battery voltage for exemplary UWB Transceivers according to embodiments of the invention. o Shallow: Moderate Sleep Level. Takes approximately 16 ps to get back to active state. Typical current consumption is 50 pA in this mode at 3.0 V battery voltage for exemplary UWB Transceivers according to embodiments of the invention. o Deep: Deep Sleep Level. Takes approximately 3 ms to get back to active state. Typical current consumption is 750 nA in this mode at 3.0 V battery voltage for exemplary UWB Transceivers according to embodiments of the invention..
  • Data Size Can be set from 1 to 124 bytes.
  • the link layer running on the EVK, HDK, WSK according to embodiments of the invention has the MCU encapsulating the data with a 4-byte header, hence the maximum limit of 124 bytes.
  • the data size and header may be different sizes / ranges.
  • Packet Rate The maximum achievable packet rate depends on the chosen sleep level, packet size, FEC level and modulation. Its upper limit is automatically set when changing any of the aforementioned settings. This limit is set according to an empirical calculation although within other embodiments of the invention this limit may be set by historical data analysis or in dependence upon the output of a machine learning algorithm.
  • Band Spacing The space between two adjacent bands’ center frequency. For example this may be set to increments of a base frequency step, e.g. 40.96 MHz.
  • Band Count The number of bands the system will sequentially hop on. The minimum is 1 and the maximum may be defined, for example 2, 3, 6, 8 etc.
  • Band Start The first band’s center frequency. . For example this may be set to increments of a frequency step, e.g. 40.96 MHz.
  • Ranging Mode This may allow users to evaluate the distance between two UWB Transceiver and employs time of flight to calculate this distance and can measure from 0.5 m up to 100 m in line of sight.
  • the ranging’s band frequencies may, for example, be 3.93 GHz for the SR1010 and 7.29 GHz for the SR1020. However, other discrete frequencies as well as multiple frequencies within the operating range of a UWB Transceiver according to embodiments of the invention may be employed. Within some instances a ranging mode may be one way ranging although within others it may be both ways with subsequent communications and averaging.
  • Figure 30 depicts ranging mode GUIs in first and second Images 3000A and 3000B for transmitter and receiver within a software application controlling and/or configuring a UWB device according to an embodiment of the invention.
  • Ranging In this mode, the user can perform distance measurements between a slave and master device. The state of the link can also be monitored. The calculated distance will appear once the master device receives valid data from the slave device.
  • Calibration This mode allows the user to change the default calibration value of the system in order to increase the accuracy of measurements given the user situation.
  • the accuracy for both Uow Output Power and High Output Power modes is given in Table 4.
  • the output power of the transmitter may be increased such as indicated in Table 4. This allows the user to change between close and long range. It is important to note that each power state may require its own calibration procedure.
  • a Plotter Function may be provided as an option, see for example Icon 3010 in Figure 30.
  • the GUI allows visualization of real time link quality monitoring plots.
  • Figure 31 depicts in first Image 3100 A a plotter mode GUI for a software application controlling and/or configuring a UWB device according to an embodiment of the invention. This provides visualization, for example of Signal Strength, Noise Floor, Link Margin, Audio Packet Delivery Rate, Link Usage and Audio Buffer Load when triggered within the Audio Mode.
  • second and third Images 3100B and 3100C wherein a user can select a time frame within the displayed range and view at increased resolution.
  • the plots show data for all bands.
  • the presented data may be filtered to one or more bands of the transmission rather than all bands employed.
  • embodiments of the invention support UWB Transceiver ASICs through providing one or more hardware evaluation kits, e.g. WSK and HDK, and one or more software development kits, e.g. SDK. Focusing to the SDK then this includes code and modules relating to:
  • Audio core mechanisms for providing clock drift compensation and sampling rate conversion • Audio core mechanisms for providing clock drift compensation and sampling rate conversion.
  • Wireless protocol stack building blocks such as a scheduler and synchronization modules and methods.
  • the EVK and HDK address packaging, design and layout of elements including component placement and signal routing, and user interfaces.
  • the SDK according to embodiments of the invention address aspects of the Link Layer including, but not limited to:
  • WPS Wireless Protocol Stack
  • the RF channels used for a transmission can vary from one time slot to the other (or not), and from one device to the other (or not). This can happen dynamically in a predetermined or random manner. More bandwidth than an application requires may be allocated to provide a retransmission margin. If the datarate the application needs is under the peak datarate achievable and no retransmissions are needed because the link is in perfect health, some timeslots will be unused and no transmissions will happen in them. On the other side, if the link is bad, transmissions will potentially occur in all timeslots, leading to a 100% link usage; the retransmission margin is used entirely. Accordingly, embodiments of the invention provide for:
  • CCA Clear Channel Assessment
  • UWB Transceivers are orchestrated at given times to transmit, to put the transceiver to sleep, and to listen for an incoming frame. It is the slave device’s job to make sure it is always synchronized to the master by continuously adjusting its duty cycling period. The master’s duty cycling period stays constant. Devices access the media in a time-division multiple access (TDMA) fashion. A typical timeslot grid for all devices within a link is shown in Image 3200 in Figure 32 wherein the actions of a Master 3210 and a series of first to third Slaves 3220 to 3240 respectively are shown for a sequential set of timeslot.
  • TDMA time-division multiple access
  • UWB Transceivers can support point-to- point, mesh and star network topologies are achieved with the system.
  • a point-to-point link example is an audio application with a unidirectional or bidirectional transmission of data over- the-air over a single link between two devices.
  • a mesh network topology example is an IoT scenario where any node can relay information between other nodes.
  • a star network topology example is an audio broadcast or multicast in which multiple devices are communicating with a master device (receiving audio from the master).
  • Another example is a gaming hub where the hub is the central node communicating with a headset, mouse and keyboard for example.
  • the inventors have established a SPI protocol core to transfer data from the external interface to the core of the UWB Transceiver.
  • Exemplary timing diagrams for read command, read data at full duplex, write and read data at full duplex and continuous write are depicted in Figure 32B in first to fourth Images 3200 A to 3200D respectively.
  • Embodiments of the invention provide for a low latency UWB multi-point to point network protocol with heterogenous datarate support.
  • a network stack according to an embodiment of the invention allows coordinated concurrent behavior by leveraging Frequency Domain Multiple Access (FDMA) and Time Domain Multiple Access (TDMA).
  • FDMA schedules provide concurrent links on different frequency channels transmitting at the same time, while TDMA schedules concurrent links on the same frequency channel but transmitting at a different time.
  • the FDMA principle can be extended within embodiments of the invention such that transmitters can operate on frequency band hopping sequences, and concurrent operation is established by transmitters having non-overlapping hopping sequences.
  • one device is designated a network coordinator, and periodically transmits a beacon.
  • the time in between beacons is subdivided into time slots.
  • a transmitter in the network has to switch frequency band to the next one in the hopping sequence, such as described above.
  • Each time slot can therefore be considered to have a number of simultaneous FDMA streams equal to the number of non-overlapping hopping sequences.
  • Each FDMA stream in a time slot is further subdivided into TDMA sub slots, allowing concurrent links to share a timeslot while using the same hopping sequence.
  • each link can occupy a lesser or greater portion of the time slot.
  • the network can be scheduled by assigning sub-slots and FDMA streams to each of the links in a network. As long as the links do not overlap in either hopping sequence or time, concurrent operation is provided. A mix of multiple low and high datarate links can therefore be supported simultaneously.
  • the software and/or firmware manages aspects of the transmission including, but not limited to: • Audio Frame-Packet Structure
  • an audio core and its API can be used standalone without depending upon the WPS, although it would be evident that when the audio is streamed over an RF link using the UWB Transceivers that the audio will make use of the WPS.
  • the audio core With respect to the audio core then its top-level entity are audio streams where each stream describes the audio flow from the production of audio samples to their consumption with the processing they must go through in between. Such an audio stream being depicted in Image 3300 in Figure 3300 from audio sample producer via audio processing to the audio sample consumer.
  • an audio device e.g. a device comprising a UWB Transceiver with associated hardware such as an EVK or HDK for example. It does not matter if the complete audio system has many audio devices and that at the system level, one audio device records audio and the other one plays it back.
  • the producer, the audio processing and consumer are all local entities.
  • audio producers and consumers are audio end points (because they are at both end of an audio stream). To be considered a valid audio end point, one must adhere to a specific audio interface.
  • An audio interface is the minimal set of functions the end-point must implement.
  • An audio end-point can be anything, as long as it produces and/or consumes audio samples. Examples of end-points may include, but not be limited to:
  • a hardware audio codec • A network stack (e.g. a WPS according to an embodiment of the invention
  • a dummy audio codec which generates a pre-recorded signal, e.g. a sine wave.
  • a UART interface for inter-board communication, where in one embodiment we can substitute a WPS according to an embodiment of the invention for a UART).
  • the audio processing box represents any operations that will modify the produced samples in some way before they are being consumed.
  • the audio core according to an embodiment of the invention provides built-in audio processing stages that a developer could use for his application by simply configuring and activating them. These processing blocks may include, but are not limited to:
  • a user may also integrate other audio processing into the audio stream, if for example, the UWB Transceiver / EVK / HDK / SDK combinations or discrete elements providing the audio core do not provide what is needed or the user wishes to use their own implementation. Accordingly, within the following description of exemplary scenarios and components of the audio an audio stream contains an audio producer, some audio processing and an audio consumer.
  • Example : Headset System Suppose we have a headset system, which is comprised of 2 audio devices (a headset and a dongle). It uses UWB Transceivers according to embodiments of the invention to provide the link between the headset and the dongle. The headset receives audio from the dongle and sends back audio to the dongle (e.g. microphone). Accordingly, there are two audio streams on the headset as depicted in first and second Images 3400A and 3400B in Figure 34 which depict the headset main audio stream and headset-microphone audio streams respectively.
  • first and second Images 3400A and 3400B in Figure 34 depict the headset main audio stream and headset-microphone audio streams respectively.
  • Example 2 Audio Loopback: This is an example where a user wishes to playback what is being recorded on the same audio device. Here, we could record what is on the Line- In of the audio codec and play it back on the Line-Out on the same codec. This is done with a single audio stream as depicted by Image 3500 in Ligure 34 which depicts the audio stream for loopback within electronic devices with UWB transceivers supporting an audio stream according to an embodiment of the invention.
  • Example 3 Multicast: An audio system can also have multiple wireless playback audio devices like in the case of audio multicasting. Considering the audio stream on the recording device, we would still see a single consumer (the WPS), because every receiving device would listen to the same audio transmission at the same time. Lrom the perspective of the recording device, all the playback devices are reachable using the same WPS connection. Ligure 36 depicts this audio stream for multicasting with electronic devices with UWB transceivers supporting an audio stream according to an embodiment of the invention.
  • Ligure 37 in first Image 3700A there is depicted system block diagrams of an electronic device with UWB transceiver supporting applications including audio streaming according to an embodiment of the invention.
  • the MCU peripherals e.g. interfaces etc.
  • the UWB Transceiver which transmits / receives wireless signals (data) to the elements within the middle layer whilst the Applications sit above this layer.
  • the Applications layer is a space controlled by a developer who wants to use the SDK.
  • the application will call the different APIs the SDK offers, such as the Audio API and the WPS API to perform the particular task / functions required.
  • the Audio Core then this requires within some embodiments of the invention the application to take care of a few things before the Audio Core starts its work.
  • These task performed by the Application may include, for example:
  • the ASIC the audio end point uses (if any) has been initialized accordingly.
  • Lor example if the ASIC is an audio codec, it has been configured to be I2S slave or master through the ASIC driver, the right audio input and sampling rate has been configured, etc.
  • the compile-time Audio Core configuration constants have been properly set. This includes some configurations about memory allocation among else.
  • the application wants to send and receive data while streaming audio, the application needs to call the WPS API directly.
  • the audio core only deals with audio streams. An exception, for example, may be if the user wants data to be piggybacked onto audio packets.
  • the Audio Core is comprised of several audio processing modules although the use of audio processing blocks that the Audio Core supports is optional and can be enabled or disabled through the Audio API.
  • the Audio application programming interface is a set of public functions that the application can call to make use of the audio core.
  • the API brings to concept of stream, endpoint and processing stage abstraction to the application.
  • the audio settings may be configured, these settings comprising for example:
  • Audio functions may for example include:
  • Second Image 3700B depicts exemplary interconnections between an Application, the Audio Core and its associated internal elements, a third party library and a library specific to the UWB Transceiver and/or SDK.
  • Figure 38 depicts an exemplary flow diagram for an audio application interfaced to UWB transceivers within electronic devices according to an embodiment of the invention.
  • the application is responsible for allocating audio memory space (heap) large enough to accommodate the memory needs of the audio core such as for audio buffering and processing. Once the audio core gets access of this audio heap, it can utilize it to "dynamically" allocate memory.
  • all memory allocation is performed by the audio core at its initialization and error checking will enable the user to be informed if the size of the audio heap is too low (or too high).
  • the audio core does not free up this memory whilst executing and no audio allocation is performed within this exemplary embodiment of the invention at a later time other than at the initialization, although within other embodiments of the invention the memory allocation may be adjusted post-initialization.
  • An exemplary data structure used to manage the memory is a queue implemented with a simply linked list. This provides flexibility and enhances performance in situations where it may be required to transfer a node from one queue to another directly.
  • First Image 3900A in Figure 39 depicts an exemplary audio stream comprising three processing stages. When processing must be performed, the producer will get an empty node (Node #1) for the producer queue and put its samples there. The first processing stage (Stage 1) will take this node as source data, process it and output the results in another empty node (Node #2) attached to the producer queue. Then, it will free Node #1 from the producer queue since the data in it is no longer needed.
  • the next processing stage (Stage 2), will take Node #2 as source data and will request a free node for its output. In this case, Node #1, now empty, will be picked. Accordingly, sufficient memory for only two nodes is needed for N processing stages.
  • the last processing stage will output its processing result directly to the consumer queue, which is a bigger queue that creates the audio latency and feeds the consumer. If a stream does not have processing at all, the producer can directly use the consumer queue as output to avoid an unnecessary intermediate copy in a producer node as shown in second Image 3900B in Figure 39.
  • a queue library for the audio core would provide, for example, functions allowing the audio core to:
  • a core may include a protocol.
  • this an audio protocol is employed when inter-audio device communication is necessary.
  • An exception may be in audio loopback on a single audio device (e.g. line-in goes to line-out of a same audio codec).
  • This protocol defines a header and a trailer for encapsulating the audio samples.
  • Protocol features may include, but not be limited to::
  • CRC cyclic redundancy check
  • a core may include statistics.
  • the audio core may support different audio related statistics, counters and ratios, such as audio packet delivery ratio and current audio buffer load.
  • a core may include endpoints.
  • an audio core may employ audio endpoints (EPs) which are used to represent "something" the audio application uses to send or receive audio samples. It can, for example, be an audio codec, a wireless protocol stack (WPS) or a UART interface.
  • EPs audio endpoints
  • WPS wireless protocol stack
  • UART UART interface
  • An EP may be defined as comprising:
  • An instance specific to the EP and its kind e.g. audio codec vs protocol stack
  • special parameters or hardware access functions i.e. an object which is an instance of this particular EP.
  • a name such as a character string to identify it in a human readable fashion.
  • an EP represents "something" that can produce and consume samples to reuse the audio interface terminology.
  • An audio codec will be represented by an EP. If there are two different audio codecs on a board, for example, there will be one EP for each of them. Essentially, each external element is an EP to the audio core. It would be evident that an EP may also contribute to multiples audio streams, e.g. it can record samples for stream A and be used to playback samples for stream B.
  • a core may include an interface.
  • the Audio Core may employ an audio interface is a set of functions that each EP must comply with in order to be compatible with the audio core. These functions may include, but not be limited to, the following:
  • this function is called when the audio core needs the EP to start consuming audio samples (e.g. playback of samples for an audio codec).
  • Control this function is used perform configurations that the audio core should take care.
  • the volume control could be something the audio core could handle instead of the application.
  • a pre -defined set of commands may be required by each or every EP.
  • a core may include one or more processing stages.
  • the Audio Core may include audio processing stages (PS) which are attached to a stream and represent operations that are performed on the audio samples after they have been produced by the Producer and before they are consumed by the Consumer.
  • PS audio processing stages
  • a PS implements a standard processing interface that the Audio Core knows about.
  • a PS may be defined by one or more characteristics which may include, but not be limited to:
  • a type that describes a category the PS belongs to e.g. SRC, CDC, etc.
  • a core may include a processing Interface.
  • the Audio Core may include a set of functions that each processing stage (PS) must comply with in order to be compatible with the audio core. These functions, may for example, be the following:
  • the Audio Core When the Audio Core processes a stream, it will cycle through every registered PS and call their set_action( ) followed by their process( ) function.
  • the set_action( ) will be used by the Audio Core to communicate to the PS the next action it needs to do.
  • These actions are pre-defined in processing action .
  • the actions the PS needs to handle varies according to its type. For example, a PS of type CDC will need to handle every PROC_ACTION_CDC_ action where a PS of type SRC will need to handle every PROC_ACTION_SRC_ action.
  • the Audio Core Once the Audio Core has called the set_action() function, it will then call the process() function, pass the samples needing processing through datajn alongside the size of the data chunk. Once the processing is done, the process() function will return the processed samples through data_out and return the number of bytes processed through its return value. If, for some reason, process( ) has not done anything on the samples, it will return 0. The Audio Core will then know that there is nothing valid from data_out (not even a copy of datajn as this would be a waste of processing cycles).
  • a core may include Clock Drift Compensation (CDC).
  • CDC Clock Drift Compensation
  • the Audio Core clock drift compensation is necessary when the audio clock from which the sampling rate is derived is different between an audio codec that records the audio samples and the one that plays them back. This being for example where the audio data is streamed or transferred via a wireless link employing UWB Transceivers according to embodiments of the invention.
  • One board will record the samples and the other one will play them back.
  • the audio clock is asynchronous between both boards codecs. This means that even if both audio master clocks are theoretically 12.288 MHz and a sampling rate of 48 kHz is configured, the effective sampling rate on one side can be 47.980 kHz and on the other side 48.030 kHz. This clock drift needs to be compensated. If not, audio glitches will occur.
  • EVKs comprise a CDC module which make use of a resampling library developed by the inventors.
  • the strategy employed by a CDC module according to an embodiment of the invention to compensate clock drift comprises a process wherein as soon as a drift is detected, the module will smoothly start resampling the samples (for example 1440 samples although other numbers may be employed either by default or dynamic configuration). At the end of the resampling period, a new sample will have been created (or dropped). Dropping a sample compensates for an audio clock on the playback device that is too slow compared to the recording one, and adding a sample compensates for an audio clock on the playback device that is too fast compared to the recording one.
  • a CDC module according to an embodiment of the invention may provide on or more capabilities including, but not limited to:
  • Fixed or variable bit sampling e.g. 16 bit only or dynamically configurable at two or more samplings such as 16 bit and 32 bit for example.
  • a core may include Sampling Rate Conversion (SRC).
  • SRC Sampling Rate Conversion
  • the Audio Core may employ a SRC to modify audio samples such that they look as if they were initially sampled at a different rate. This is useful, for example, if a hardware audio codec is configured with a sampling rate frequency of 48 kHz, but a 16 kHz stream is needed for a microphone. Most codecs can only have a single sampling rate for its record and playback channels.
  • the inventors have established an SRC within their EVKs which provides for capabilities including, but not limited to 16-bit sampling (although other SRCs may provide different bit sampling with SRC or bit rate and sampling rate conversions, e.g. 48 kHz 16 bit to 16 kHz 24 bit for example), interpolation and decimation.
  • UWB Transceivers may be employed as a communication medium, regardless of the underlying interfaces or nature of the data to be transmitted.
  • Audio multicast from a master device to 2 or more slave nodes.
  • the audio multicast system e.g. star network
  • the audio stream can be processed differently on sink devices (end nodes) to lead to different playback per end node.
  • the stream playback is synchronized between the end nodes (high sync accuracy, sub 1ms).
  • the audio stream latency is variable and can range from few milliseconds to tens of milliseconds.
  • Audio broadcast from a master device to 2 or more slave nodes o
  • the audio broadcast system (e.g. star network) allows to playback audio on end nodes which receives the data through a SPARK link (i.e. through a UWB Transceiver according to an embodiment of the invention.
  • the audio stream can be processed differently on sink devices (end nodes) to lead to different playback per end node.
  • the stream playback can be synchronized between the end nodes (high sync accuracy, sub 1ms).
  • the audio stream latency is variable and can range from few milliseconds to tens of milliseconds.
  • the broadcast system is a best effort transmission, meaning that if one of the end nodes misses a packet, it is not retransmitted.
  • the Coordinator moves on to the next packet.
  • Audio point to point link unidirectional or bidirectional, any audio stream settings (sampling rate, bit depth, etc.) o
  • a point-to-point (P2P) audio link is the base of all audio applications.
  • a P2P according to embodiments of the invention allows adjustment of audio stream settings such as sampling rate, latency (buffering) or channel count.
  • the system can perform various digital processing steps on an audio stream: sampling rate conversion, clock drift compensation, volume adjustments, mixing, interface loopback, software generation of audio signal, fading and compression.
  • a basic terminal available in SDKs (and/or EVKs and/or HDKs) according to embodiments of the invention maps commands with letters.
  • An extended set of commands can be used by prepending a reserved character, allowing for more commands than the standard ASCII characters set permits.
  • An argument parser can treat the provided arguments as different types such as a Boolean, byte, half-word or word.
  • the terminal may use a serial interface such as UART or USB for example.
  • An expanded terminal available in SDKs (and/or EVKs and/or HDKs) maps commands with words and has a “directory-type” structure.
  • An argument parser can treat provided arguments as different types such as a Boolean, byte, half-word or word.
  • the terminal may use a serial interface such as UART or USB for example.
  • IoT tags are nodes that work within a mesh network topology and that can display short messages or images on a display. A typical scenario would be a retail store with remotely updated price tags for example.
  • Sensor nodes are devices that can work in a P2P, star or mesh network topology and that gather various information.
  • a sensor node could provide temperature, pressure, humidity, light level, sound level and other measurements to a central “hub device.” That hub device can then process that data, display it or simply transfer it on any other network (e.g., bridging between a UWB Transceiver according to an embodiment of the invention and Ethernet for example).
  • Battery-less sensors are systems consisting of a microcontroller, sensors (such as described with respect to the Wireless Sensor Kit (WSK) 1100 as described in respect of Figure 11) and a UWB Transceiver according to embodiments of the invention powered by a solar harvesting system.
  • This system allows to harvest solar energy using a solar panel and using this energy to recharge an array of ceramic capacitors or a supercapacitor.
  • the microcontroller receives data from sensors, sends them to UWB Transceiver according to embodiments of the invention, and controls the solar harvesting system such as capacitor voltage and solar panel voltage.
  • a charging algorithm takes into account those voltages, and adapts the usage of the UWB Transceiver according to embodiments of the invention and the sensors according to the available voltage, allowing the system to be autonomous and optimized over time, without any battery. Such capabilities being supported by the ultra-low power consumption of UWB Transceivers according to embodiments of the invention.
  • Bare metal stack (application, wireless protocol stack) o
  • the application employed within embodiments of the invention, such as within the EVK for example, is built directly over a device driver/hardware abstraction layer. This allows for enhanced performances such as faster response times, reduced system latency, low memory footprint, and code simplicity. Processing that has critical timing requirement is driven through hardware or software interrupts.
  • RTOS Real-time operating system
  • application wireless protocol stack
  • a RTOS is employed to orchestrate execution of the various modules forming the system, e.g. such as within an SDK according to embodiments of the invention.
  • Heterogeneous payloads e.g. audio + other data in the same payload
  • Payload content can be defined by multiple applications using the WPS at the same time and combined before being sent over-the-air. This leads to heterogeneous payloads.
  • the application payload can be homogeneous.
  • a radio may provide an automated acknowledgment mechanism. This ensures the quickest response possible when a packet is successfully received. Further, according to embodiments of the invention, a payload may be piggybacked onto the ACK frame and the system may do so when the scenario is appropriate.
  • An Automatic Repeat-reQuest (ARQ) mechanism may leverage the auto- ACK feature Automatic Repeat-reQuest although it may also employ a standard frame to send the acknowledgement.
  • the transmission can combine the Over-the-Air (OTA) and successfully be received e.g., with a star topology with 3 devices, 2 receivers can acknowledge at the same time.
  • OTA Over-the-Air
  • a single synchronous network can be formed by multiple independent or dependent links.
  • By orchestrating all the links in a single schedule embodiments of the invention can ensure that all links have their place reserved.
  • the concurrency mechanisms are less important in this scenario.
  • An example of dependent links inside a single network is a star application, where the central device maintains a P2P link with several other independent devices.
  • An example of independent links sharing a single schedule is a multiple independent P2P links application, where several pairs of devices share the schedule, but have no relation with each other. Those pairs are synchronized through a beaconing mechanism.
  • Beaconless network any device can communicate at any given time, as long as the air is free. Devices do a clear channel assessment to see if transmission can happen or not. If not, transmission is postponed or canceled. This suits low bandwidth applications such as IoT, where transmissions rarely occur.
  • Payload size greater than 128 bytes (radio feature that allows up to 256 bytes) o
  • Typical payloads within according to embodiments of the invention can range from a couple of bytes up to 128 bytes. However, some projects require the use of payloads >128 bytes to achieve specific goals. These can be supported by according to embodiments of the invention.
  • Event based transmissions (transmit once ready, otherwise skip slot) o Applications give data to the radio to be sent OTA. If the wireless protocol stack schedules transmission but has not received any data from the application side, nothing will be transmitted over the air. This means that when an event occurs, the data will be sent as soon as possible by the WPS, but if no data is available nothing happens.
  • Constant transmission isochronous relative to link schedule, never skip slot
  • Some applications may want to always transmit when possible. This means that the application will always provide data to the WPS for every scheduled transmission. So instead of being triggered by an external event, data generation happens constantly.
  • Dynamic link parameters adjustments o
  • a methodology exists, e.g. through beacons or within data transmitted in headers etc., for the orchestration of changes within the network(s) such as change of modulation, FEC level, etc. This may be between each pair of devices communicating together within a P2P or each P2P within a mesh network for example.
  • this can be exploited to obtain optimum performance in different concurrency scenarios.
  • Dynamic application adjustments to compensate for degraded link performances o
  • the concept of “fallback mode” according to embodiments of the invention implementable at the application level allows for selecting reduction of the application data throughput. For example, dynamically adding audio compression.
  • Gain loop o
  • a control loop is implemented which allows the gain of the radio to be adjusted in real-time in dependence upon one or more RF metrics.
  • a single hardware implementation e.g. EVK, HDK, WSK, can support multiple UWB Transceivers according to embodiments of the invention at the same time in order to achieve different objectives.
  • a headset may employ a dual-radio system wherein the pair of radios are used to maximize the coverage.
  • the inventors have established algorithms to optimally choose the transmitting and receiving radios in such instances.
  • Ranging could be combined with other applications in such a way that distance between transmitter and receiver is measured while transmitting other data.
  • a transceiver could send an audio stream to a remote device while measuring the distance from the other device.
  • Range could serve as a metric to determine some actions regarding the audio stream are required (fallback mode).
  • P2P ranging can also be extended to more complex real-time localization systems and provide 2D or 3D positioning. Such ranging information may be distributed within a network automatically allowing each node to perform specific 2D or 3D positioning as required.
  • UWB Transceivers can provide for low latency. Accordingly, for the instance of audio streaming the inventors performed a series of measurements to simulate an exemplary gaming hub implementation of a gaming headphone system (Gaming Hub). This employed a pair of UWB Transceivers according to embodiments of the invention mounted to EVKs according to embodiments of the invention.
  • the wireless protocol stack (WPS) running on the Gaming Hub was configured for a l-to-3 star topology.
  • the Hub is the master node and the Headset, Mouse and Keyboard are the slave nodes. It is the slave device’s job to make sure it is always synchronized to the master by continuously adjusting its duty cycling period.
  • the master’s duty cycling period stays constant.
  • the Mouse downlink (Hub to Mouse) and Mouse uplink (Mouse to Hub) payload data rate is 256 kbps.
  • the Keyboard downlink (Hub to Keyboard) and Keyboard uplink (Keyboard to Hub) payload data rates were similarly 256 kbps.
  • the devices had an audio transmission buffer that can contain up to 24 audio frames and another buffer dedicated to transmission of human interface device (HID) frames that can contain up to 5 frames. These buffers will fill if the link conditions are poor. If the audio transmission buffer is full, the newer audio frames will overwrite the oldest audio frames. If the HID transmission buffer is full, data generation stops until the queued frames are successfully sent over-the-air.
  • HID human interface device
  • First Graph 4000A depicts the audio channel latency.
  • Second Graph 4000B depicts channel latency for the microphone within the headset.
  • Third Graph 4000C depicts the shortest latency for the HID channel
  • Fourth Graph 4000D depicts the average latency of the HID channel
  • First External Interface 4110 such as a PC for example
  • Second External Interface 4120 such as another PC for example
  • First Host 4130 provided by an EVK carrier board without UWB Transceiver;
  • First SPARK module 4140 comprising an EVK with UWB Transceiver and antenna
  • Second SPARK module 4150 comprising an EVK with UWB Transceiver and antenna
  • Second Host 4160 provided by an EVK carrier board without UWB T ranscei ver.
  • the first Host 4130 and first SPARK module 4140 providing a first SPI Uink
  • second Host 4160 and Second SPARK module 4150 providing a second SPI Uink.
  • Figure 42 depicts exemplary timing information for the UWB interface employed within the system of Figure 41. As depicted a timeslots superframe comprises 16 equally sized timeslots each lasting 4 ms which is repeated. In this diagram, each timeslot is separated by vertical dotted lines and at the bottom, the timeslot duration as well as the size of the transmitted application payload are presented.
  • Figure 43 depicts an exemplary data structure for the UWB transmission within the system of Figure 41.
  • FIG. 44 depicts a timing diagram for the SPI pipe according to an embodiment of the invention showing half-duplex transfer, pausing and full duplex transfer. Accordingly, when the user wants to send data over the RF channel (Data mode) the following sequence is performed.
  • the SPI Master (user’s device) sends the Send Data command followed by the data it needs to send on the MOSI line.
  • DR Data Ready
  • MISO Master In Slave Out
  • the master sends the Send Data command followed by the data it needs to send in this Master Out Slave In (MOSI).
  • MOSI Master Out Slave In
  • FIG. 45 depicts a timing diagram for the SPI pipe to allow an SPI master device to write continuously without stopping any transaction. Accordingly:
  • the first byte received by the master is the size followed by the data.
  • MISO MISO
  • the SPI Master should stop duty cycling the SCLK line to let the SPI slave successfully send data over-the-air to free its internal memory. If the SPI master toggles the CS pin while the FC pin is low, the SPI slave will split the transfer at that point. In that instance, any intermediate data that may have been sent while FC was low could be used to create an RF packet of smaller size than expected. Once the FC pin returns low, the SPI master can resume duty cycling the SCLK line. If the RF link is not operational, the SPI slave will not be able to free its internal memory and the FC pin will stay high.
  • Figure 46 depicts a timing diagram for the SPI pipe where an SPI master device is reading slave device configuration parameters. Accordingly:
  • the master sends a read command and duty cycles the SCLK line to keep the line active. During this time, the CS line must be held low.
  • the slave sends the READY signal followed by the data.
  • the length of the data depends on the command and can be found in the Command List section.
  • Figure 47 depicts a timing diagram for the SPI pipe where an SPI master device is writing slave device configuration parameters. Accordingly:
  • the master sends a write command associated with the configuration it wants to change. During this time, the CS line must be held LOW.
  • Figure 48 depicts measured values for a UWB link employing UWB transceivers according to an embodiment of the invention extracted via the SPI pipe extracted by a terminal. Experimental measurements were also performed to establish the latency from SPI to SPI via the UWB Transceivers according to embodiments of the invention. The latency was measured from SPI to SPI using a logic analyzer with an incrementing test sequence used to correlate the packets on both sides and a variable attenuator employed to adjust link quality.
  • Figure 49 depicts the measured results in first and second Images 4900A and 4900B as obtained upon a logic analyzer for the SPI to SPI interface with UWB transceivers according to an embodiment of the invention. Accordingly, with a good link the latency was below 1 ms, with Figure 49 depicting the result as 0.659 ms of latency.
  • FIG. 50 depicts the emitted power spectrum of the UWB transceiver providing a 3Mbps unidirectional link wherein the measured output power taking into account the antenna gain (2.5 dB) and the loss in the measurement setup (0.5 dB), the measured power limit must below -44.3 dBm/MHz.
  • the output power for the default UWB Transceiver configuration has a maximum at -45.52 dBm/MHz.
  • FIG. 51 there is depicted an exemplary configuration of a head mounted device (HMD) 5110 interfaced to a pair of controllers, first and second Controllers 5120 and 5130 respectively, via UWB transceivers according to an embodiment of the invention.
  • HMD head mounted device
  • DL downlink
  • UL uplinks
  • Figure 52 depicts an exemplary structure of a superframe for UWB transmissions between UWB transceivers according to an embodiment of the invention for the system depicted in Figure 51.
  • the timeslots superframe lasts 6 ms and is repeated indefinitely.
  • the last transmission of the HMD in the superframe is replaced by a beacon.
  • each timeslot is separated by vertical dotted lines and at the bottom, you can see the timeslot duration as well as the size of the transmitted application payload. It is to be noted that the length of the timeslot is not the actual RF airtime and that the application payload size shown does not account for extra protocol header bytes added by the WPS encapsulation.
  • the normal application payload data rate needed for the HMD 5110 is 150 kbps, but the employed timeslot schedule allows for a 181 kbps data rate. This means that 17.36% of the bandwidth can be allocated for retransmissions.
  • the normal application payload data rate needed is 300 kbps per controller, but the implemented schedule allows for 648 kbps per controller, e.g. for each of first and second Controllers 5120 and 5130 respectively. This means that 53.75% of the bandwidth can be allocated for retransmissions.
  • Frames are segmented into 3 equal size chunks to fully utilize the transmitter spectrum and the full frame is reconstructed by the HMD upon reception of the 3 chunks.
  • the HMD 5110 has a transmission buffer that can contain up to 8 frames. This buffer will fill if the link conditions are poor. Once it is full, the data generation will pause until space is made in the buffer by successfully sending frames OTA.
  • Each controller e.g. first and second Controllers 5120 and 5130 respectively, has no buffering but needs to manage the 3 ms lifetime of the incoming frames. If after 3 ms it cannot get the whole frame through because the wireless link is not healthy, it will drop the remaining frame chunks and start trying to transmit the first chunk of the next frame.
  • the WPS obtains the application data, it will encapsulate it in the following manner depicted in Figure 53 which depicts the exemplary structures for data frames, acknowledgement, beacon and controller data frames within the superframe for UWB transmissions between UWB transceivers according to an embodiment of the invention in first to fourth Images 5300A to 5300D respectively.
  • Initial synchronization is done using the 6 ms beacon. If HMD data is sent during initial synchronization, it will speed up the synchronization process since more frames on which the slaves can synchronize are being sent by the master. The calculation for expected maximum initial synchronization time is given by Equations (1) and (2) respectively if no HMD data is being sent.
  • Table 5 summarises the transmission events.
  • the configuration was then characterised with a system composed of a USB controlled variable attenuator and a power divider connected to the HMD and both controllers using SMA cables.
  • the total attenuation of the setup was measured with a network analyzer to calibrate the total losses at all frequencies.
  • the reference antenna on the EVKs employing UWB Transceivers according to embodiments of the invention had an antenna gain of 2.5 dB, which is used to calibrate the effective radiated output power on the HMD and Controllers to conform to the regulated emissions.
  • a balun was used on the HMD and Controller side with 0.7 dB of insertion loss.
  • the configured RF bandwidth was 1500 MHz.
  • the UL was limited by the peak power UWB spectrum regulation, which limits the symbol power of the controller to 3 dBm of radiated power at the transmitter antenna.
  • the DL was limited by the average power regulation of -41.3 dBm/MHz over 1ms. This average power is the sum of the HMD data link, HMD ACK and the beacon. These links all use different power settings to optimize the system performances.
  • the results are presented in Figures 54 to 56 which depict the measured power error rates. In each of these Figures Band 1 is -6758 MHz, Band 2 is -7291 MHz and Band 3 is -7823 MHz.
  • Figure 54 presents results in first and second images 5400A and 5400B for the HMD 5110 with 10% pre-ARQ (Automatic Repeat-reQuest) and 0.01% post-ARQ respectively.
  • Figure 55 presents results in first and second images 5500A and 5500B for the first Controller 5120 with 1% pre-ARQ and 0.01% post-ARQ respectively.
  • Figure 56 presents results in first and second images 5600A and 5600B for the second Controller 5130 with 1% pre-ARQ and 0.01% post-ARQ respectively.
  • Figure 59 depicts logic analyzer screen captures within which one can see the packets transmitted by Controller #1 when looking at the row labeled Cl TX. Then, by looking for a pulse within 3 ms after in row label HMD RX Cl, you can see if it has been received correctly within the correct time frame. If a frame is dropped by the controller because its 3 ms lifetime is expired, you will see a pulse in the Cl Drop row. If a drop happens, the HMD RX C* of the Controller in question will be missing a pulse. Also note that the C* Drop pulse can occur outside the 3ms window. T This is due to the fact the HMD will only discard packets once it starts to receive a new one. This behavior does not affect the maximum packet latency in any way.
  • Figures 59 depicts latency measurements obtained when a latency mode of the UWB transceivers within the configuration depicted in Figure 51.
  • First and second Images 5900A and 5900B being when the latency measurement mode is deactivated and third image 5900C is when the latency measurement mode is activated.
  • a timer referred to as the PWM timer
  • the PWM timer is configured with the same period as the beacons (6 ms) and a 50% duty cycle on every microcontroller.
  • the HMD 5110 resets the PWM timer with a constant offset when it receives the reply from a controller, e.g. one of first and second Controllers 5120 and 5130 respectively. In this manner, any error between the microcontroller’s and the radio’s timer sources can be corrected.
  • the microcontroller timer source is 12.288MHz ⁇ 20ppm and the radio’s timer source is 32.768kHz ⁇ lOOppm.
  • a pin outputs a clock signal that is synchronized with the HMD’s signal.
  • the jitter on the controllers’ signal compared to the HMD’s signal should be lower than 2 ps.
  • Figure 60 depicts an exemplary synchronization measurement between UWB transceivers within the configuration depicted in Figure 51.
  • the upper trace is the rising edge of the HMD 5110 signal whilst the middle and lower traces are the first and second Controllers 5120 and 5130 respectively. From this it is evident that the jitter is approximately 1 ps on each of the first and second Controllers 5120 and 5130 respectively.
  • Gain Loop 6100 As noted above the gain within a UWB Transceiver according to an embodiment of the invention may employ a gain loop to dynamically adjust this.
  • exemplary Gain Loop 6100 comprising first to twelfth stages 6105 to 6160 respectively. These comprising:
  • Second stage 6110 wherein the Gain Loop 6100 calculates the normalized gain of the received frame in dependence upon the data acquired from third to fifth stages 6115 to 6125 respectively wherein the process proceeds to sixth stage 6130;
  • Table 8 below depicts an exemplary gain table as used within a gain loop such as Gain Loop 6100.
  • Ligure 62 there is depicted a time slot structure and scheduler structure according to an embodiment of the invention together with associated API commands and usage.
  • Ligure 63 depicts an insertion scheme according to an embodiment of the invention for inserting a beacon within a series of time slots within a wireless link.
  • Figure 64 depicts a time slot incrementing structure according to an embodiment of the invention which is triggered upon the calling of “increment time slot” within the API, this being one of the API commands depicted in Figure 62. The flow for the process being described at the top Figure 64.
  • FIG. 65 there is depicted the frequency versus time performance of prior art audio transmission protocols relative to an embodiment of the invention relative to an original compact disc (CD) quality source providing a discrete 10kHz tone.
  • First image 6500A depicts the original content plotted as frequency content versus time.
  • Second image 6500B depicts the resulting received audio using Audio Processing Technology (referred to as aptX) algorithms (a family of proprietary audio codec compression algorithms owned by QualcommTM) whilst third image 6500C depicts the received audio from a standard Bluetooth Classic link.
  • aptX Audio Processing Technology
  • fourth image 6500D depicts the received audio from a UWB link exploiting embodiments of the invention where it has significantly lower audio content across the frequency range apart from the underlying tone. Accordingly, improved audio quality and reproduction arise from the UWB link exploiting embodiments of the invention.
  • First image 6600A depicts the original content plotted as frequency content versus time showing the periodic impulses.
  • Second image 6600B depicts the resulting received audio using the aptX algorithms whilst third image 6600C depicts the received audio from a standard Bluetooth Classic link.
  • first image 6600A depicts the original content plotted as frequency content versus time showing the periodic impulses.
  • Second image 6600B depicts the resulting received audio using the aptX algorithms whilst third image 6600C depicts the received audio from a standard Bluetooth Classic link.
  • each significant audio content is present at other times other than the discrete impulse points, this being across all frequencies with aptX and predominantly low frequencies with Bluetooth Classic.
  • fourth image 6600D depicts the received audio from a UWB link exploiting embodiments of the invention where it has significantly lower audio content across the frequency range at all times other than the periodic impulses. Accordingly, improved audio quality and reproduction arise from the UWB link exploiting embodiments of the invention.
  • the aptX implementation provides approximately 40-100ms latency whereas with Bluetooth Classic typical latencies are 100- 300ms (relative to an approximate 32ms lowest level in ideal circumstances).
  • typical latencies are 100- 300ms (relative to an approximate 32ms lowest level in ideal circumstances).
  • AirpodsTM a latency of approximately 140-200ms has been measured by the inventors.
  • UWB link exploiting embodiments of the invention achieves a latency of approximately 5ms.
  • UWB links exploiting embodiments of the invention can provide users with an immersive wireless, video and/or gaming experience at lower latency, lower power, with increased data rates and integrated ranging. Further, UWB links exploiting embodiments of the invention yield lower electromagnetic interference and provide / support coexistence with Wi-Fi etc.
  • UWB links exploiting embodiments of the invention can provide bi directional uncompressed audio (e.g. headset / microphone) at 48kS/s with 16 bit stereo (headset) and 48 kS/s 16 bit mono (microphone) with the capability for 96 kS/s 24-bit stereo and 96 kS/s 24-bit mono without any compression, down sampling or masking.
  • headset / microphone bi directional uncompressed audio
  • headset 16 bit stereo
  • microphone 48kS/s 16 bit mono
  • Table 9 exemplary gaming hub modes are presented for UWB links exploiting embodiments of the invention.
  • Table 10 below compares UWB links exploiting embodiments of the invention with Bluetooth Low Energy and two UWB IEEE standards.
  • Implementation of the techniques, blocks, steps and means described above may be done in various ways. For example, these techniques, blocks, steps and means may be implemented in hardware, software, or a combination thereof.
  • the processing units may be implemented within one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), processors, controllers, micro-controllers, microprocessors, other electronic units designed to perform the functions described above and/or a combination thereof.
  • ASICs application specific integrated circuits
  • DSPs digital signal processors
  • DSPDs digital signal processing devices
  • PLDs programmable logic devices
  • FPGAs field programmable gate arrays
  • processors controllers, micro-controllers, microprocessors, other electronic units designed to perform the functions described above and/or a combination thereof.

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  • Computer Networks & Wireless Communication (AREA)
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Abstract

Les systèmes à bande ultralarge (UWB) sont bien adaptés à des applications telles que des interconnexions périphériques et de dispositifs, des réseaux de capteurs, des systèmes de commande et de communication, des systèmes médicaux et des réseaux personnels. Alors que les niveaux d'émission autorisés par les agences de réglementation sont des systèmes UWB à faible contrainte qui favorisent des applications à courte portée, d'autres applications peuvent être considérées lorsque les restrictions réglementaires sont moins strictes et/ou inexistantes pour répondre à des exigences militaires et civiles pour des communications entre des individus, des dispositifs électroniques, des centres de commande et des systèmes électroniques, par exemple. En conséquence, des émetteurs à bande ultralarge, des récepteurs UWB et des émetteurs-récepteurs UWB fournissent une configuration et une gestion que les dispositifs électroniques rendent flexibles, tels que des dispositifs électroniques portables, des dispositifs électroniques fixes, et des capteurs, par exemple, pour permettre leur déploiement uniquement dans des systèmes autonomes exploitant uniquement la récolte solaire. Des protocoles, des architectures, des systèmes de commande ainsi que des kits de développement de logiciels et/ou des kits de développement de matériels sont décrits, ce qui permet d'obtenir des configurations flexibles et à complexité réduite de radios sans fil UWB dans une large gamme de dispositifs.
PCT/CA2022/050510 2021-04-05 2022-04-05 Procédés et systèmes de communication à bande ultralarge (uwb) WO2022213183A1 (fr)

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Citations (4)

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US20060176093A1 (en) * 2005-02-07 2006-08-10 Samsung Electronics Co., Ltd. Automatic gain control apparatus and method in an orthogonal frequency division multiple access sytem
US20060262840A1 (en) * 2005-05-20 2006-11-23 Wang Yi-Pin E Method and apparatus for transmit power control
US20090046607A1 (en) * 2006-01-31 2009-02-19 Posdata Co., Ltd. Automatic gain control apparatus and method in wireless telecommunication system based on time division duplex
CN107645283A (zh) * 2016-07-19 2018-01-30 炬芯（珠海）科技有限公司 一种自动增益控制方法及装置

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US20060176093A1 (en) * 2005-02-07 2006-08-10 Samsung Electronics Co., Ltd. Automatic gain control apparatus and method in an orthogonal frequency division multiple access sytem
US20060262840A1 (en) * 2005-05-20 2006-11-23 Wang Yi-Pin E Method and apparatus for transmit power control
US20090046607A1 (en) * 2006-01-31 2009-02-19 Posdata Co., Ltd. Automatic gain control apparatus and method in wireless telecommunication system based on time division duplex
CN107645283A (zh) * 2016-07-19 2018-01-30 炬芯（珠海）科技有限公司 一种自动增益控制方法及装置

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